I N T E R N AT I O N A L S U RV E Y
OF BUILDING ENERGY CODES
The lead Commonwealth
agency on greenhouse
matters
I N T E R N AT I O N A L
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
ISBN 1 876536 32 2
© Commonwealth of Australia 2000
This work may be reproduced in whole or part for study or
training purposes subject to the inclusion of an
acknowledgment of the source and no commercial usage or
sale. Reproduction for purposes other than those named
above requires the permission of the Australian Greenhouse
Office. Requests and inquiries concerning reproduction rights
should be addressed to:
The Communications Manager
Australian Greenhouse Office
GPO Box 621, Canberra ACT 2601
For additional copies of this document, please contact the
Australian Greenhouse Office Infoline on 1300 130 606.
This publication is also available on the Internet
Acknowledgments
The study was produced for the Australian Greenhouse
Office by the Office of the Australian Buildings Codes Board.
While every effort has been made to ensure accuracy and
completeness, no guarantee is given, nor responsibility taken
by the Commonwealth for errors or omissions in the report,
and the Commonwealth does not accept responsibility in
respect of any information or advice given in relation to or
as a consequence of anything contained here.
The Australian Building Codes Board wishes to acknowledge
the valuable assistance provided by the overseas contributors
listed in Appendix A.
Design Wingrove Wingrove Design
Photos courtesy of the Housing Industry Association,
Michael Shaw and Mirvac Lend Lease Village Consortium -
at the following address:
Developers of Newington, the Sydney 2000 Olympic Village.
www.greenhouse.gov.au/energyefficiency/buildings
Background Image: courtesy of Robert Peck von Hartel Trethowan
I N T E R N AT I O N A L
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
CONTENTS
i
List of figures
vi
Abbreviations
vii
1
INTRODUCTION
2
2
SCOPE AND METHODOLOGY
4
2.1
Scope
4
2.2
Methodology
4
3
TERMINOLOGY
7
3.1
Performance Requirements
7
3.2
Alternative Solution
8
3.3
Ventilated Buildings
8
4
UNITED KINGDOM
10
4.1
Regulatory Framework
10
4.2
Scope
11
4.3
Categories
11
4.4
Dwellings
11
4.4.1
Elemental Method
11
4.4.2
Target U-value Method
12
4.4.3
Energy Rating Method
12
4.4.4
General requirements for dwellings
13
4.5
Buildings Other Than Dwellings
14
4.5.1
Elemental Method
14
4.5.2
Calculation Method
14
4.5.3
Energy use Method
15
4.5.4
General requirements for buildings other than dwellings
15
5
NEW ZEALAND
5.1
Regulatory Framework
17
5.2
Current Requirements
17
5.2.1
Scope
17
5.2.2
Houses
17
5.2.3
Buildings other than houses
17
5.3
Proposed Future Requirements
17
5.3.1
Alternative solution
18
5.3.2
Compliance with the approved documents
18
5.3.2.1
Verification Method
18
5.3.2.2
Prescriptive requirements of referenced documents
19
I N T E R N AT I O N A L
ii
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
5.3.3
NZS 4218 - 1996 Housing and small buildings
19
5.3.3.1
Schedule Method
19
5.3.3.2
Calculation Method
20
5.3.3.3
Modelling Method
20
5.3.4
NZS 4243 - 1996 Large buildings
21
5.3.4.1
Schedule Method
21
5.3.4.2
Calculation Method
21
5.3.4.3
Modelling Method
22
5.3.5
NZS 4306 - 1996 Domestic hot water
22
5.3.5.1
Electric storage water heaters
23
5.3.5.2
Gas water heaters
23
5.3.5.3
Installation
23
5.4
Use Of Accredited Products Or Methods
23
6
UNITED STATES OF AMERICA
25
6.1
Regulatory Framework
25
6.2
Energy Codes In Use
25
6.3
Model Energy Code (MEC)
26
6.3.1
Scope
26
6.3.2
Exemptions
27
6.3.3
Compliance paths
27
6.3.4
Mandatory requirements
27
6.3.4.1
Building envelope
27
6.3.4.2
Identification marking
27
6.3.4.3
Heating and cooling
28
6.3.4.4
Service water heating
28
6.3.4.5
Electric systems
28
6.3.5
Prescriptive package approach
28
6.3.6
Trade-off approach
29
6.3.7
Software approach
29
6.4
International Energy Conservation Code
30
6.4.1
Introduction
30
6.4.2
Residential buildings
30
6.4.2.1
Annual Energy Consumption Method
30
6.4.2.2
Building Envelope Method
31
6.4.3
Commercial buildings
32
6.4.3.1
Introduction
32
6.4.3.2
The approaches contained in ASHRAE/IES
32
6.4.3.3
Design by acceptable practice for commercial buildings.
35
I N T E R N AT I O N A L
7
iii
S U R V E Y
O F
B U I L D I N G
E N E R G Y
CALIFORNIA ENERGY CODE
C O D E S
38
7.1
Regulatory Framework
38
7.2
Scope
38
7.3
Categories of Buildings
38
7.4
Climate Zones
38
7.5
Non-Residential, High-Rise Residential, and Hotel/Motel Buildings
39
7.5.1
Mandatory provisions
39
7.5.2
Performance approach
39
7.5.3
Prescriptive approach
40
7.6
Low-Rise Residential Buildings
41
7.6.1
Mandatory provisions
41
7.6.2
Performance approach
42
7.6.2.1
Determine the allowable energy budget
42
7.6.2.2
Determine the annual energy budget
42
7.6.3
Prescriptive approach (alternative component package)
42
7.7
All Buildings - Mandatory Provisions
43
7.8
Semi-Conditioned Non Residential Buildings
44
7.9
New Construction In Existing Buildings
45
7.9.1
Non residential, high-rise residential, and hotel/motel buildings
45
7.9.1.1
Additions
45
7.9.1.2
Alterations
46
7.9.2
Low-rise residential buildings
46
7.9.2.1
Additions
46
7.9.2.2
Alterations
46
7.9.3
Semi-conditioned buildings
46
8
HAWAII
48
8.1
Regulatory Framework
48
8.2
Ceiling heat gains
48
8.3
Natural Ventilation
48
8.4
Air Leakage
48
8.5
Swimming Pools and Spas
49
8.6
Testing, operating and Maintaining Information
49
8.7
Economic Calculations
49
9
CANADA
51
9.1
Regulatory Framework
51
9.2
Model National Energy Code of Canada for Houses - 1997
52
9.2.1
Scope
52
9.2.2
General provisions
52
9.2.3
Mandatory measures
52
9.2.3.1
Building envelope
53
9.2.3.2
Lighting
53
9.2.3.4
Heating, ventilation and HVAC systems
53
I N T E R N AT I O N A L
iv
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
9.2.3.5
SWH systems
53
9.2.3.6
Electrical power
53
9.2.4
Prescriptive path
53
9.2.4.1
Building envelope
53
9.2.4.2
HVAC system
54
9.2.5
Performance path
54
9.2.5.1 Building energy performance method
54
9.3
Model National Energy Code of Canada for Buildings - 1997
55
9.3.1
General provisions
55
9.3.2
Mandatory measures
55
9.3.2.1
Building envelope
55
9.3.2.2
Lighting
55
9.3.2.3
HVAC systems
55
9.3.2.4
SHW systems
56
9.3.2.5
Electrical power
56
9.3.3
Prescriptive path
56
9.3.3.1
Building envelope provisions
56
9.3.3.2
HVAC, lighting and SHW system
57
9.3.4
Performance path
57
9.3.4.1 Building energy performance compliance
57
10
CANADA - ONTARIO
59
10.1
Regulatory Framework
59
10.2
Houses And Small Buildings
59
10.3
Other Buildings
60
11
SINGAPORE
62
12
AUSTRALIA
64
12.1
Regulatory Framework
64
12.2
Scope of Energy Efficiency Measures
65
12.3
Performance Requirements
65
12.4
Australian Capital Territory
65
12.4.1
New buildings
65
12.4.2
Additions to buildings
65
12.4.3
Exemptions
65
12.5
South Australia
66
12.5.1
Ministers Specification South Australia SA2.1
66
12.5.1.1 Application
66
12.5.1.2 Verification Method
66
12.5.1.3 Insulation requirements of AS2627.1
66
12.5.1.4 Insulation requirements of the Ministers Guideline
67
12.5.1.5 Exemptions
68
I N T E R N AT I O N A L
v
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
12.6
Victoria
68
12.6.1
Insulation requirements
68
12.6.2
House energy rating
69
12.6.3
Exemptions
69
12.6.4
Other requirements
69
13
CONCLUSIONS
71
13.1
13.2
13.3
13.4
13.5
13.6
13.7
13.8
13.9
13.10
13.11
13.12
13.13
Scope and Format
Regulatory Approach - General
Regulatory Approach - Houses
Regulatory Approach - Other Buildings
Stated Objective Or Philosophy
Performance Measures
Stringency Measures And Levels
Consideration Of Fuel And Construction Costs
Use Of Standard Buildings, Assumptions, Software
Exemptions / Limitations
How "Ventilated Buildings" Are Handled
Extent Of Geographic Zones
Envelope - General
71
71
72
72
72
73
73
73
73
74
74
74
74
13.13.1 Thermal performance of elements
75
13.13.2 Housing
75
13.13.3 Other buildings
75
13.13.4 Air tightness
75
13.14
13.15
13.16
13.17
13.18
13.19
13.20
13.21
13.22
13.23
76
76
76
76
76
77
77
77
77
77
HVAC System
Lighting - Housing
Lighting Systems - Other Buildings
Metering And Monitoring Facilities
Lifts
SWH Systems
Other Equipment
Maintenance
Financial Criteria
Australian Variations And Additions
I N T E R N AT I O N A L
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
APPENDICES
Appendix A List of Overseas Contributors
79
Appendix B List of References
81
Appendix C Energy Codes Adopted by Individual States of the USA
83
Appendix D Energy Efficiency Requirements in Overseas Codes
88
LIST OF FIGURES
Figure 1
Extract from Approved Document L - Performance requirements L1
Figure 2
UK Energy Code compliance routes for dwellings
11
Figure 3
Table 1 from Approved Document L
12
Figure 4
Table 4 from Approved Document L
13
Figure 5
UK Energy Code compliance routes for buildings other than dwellings
14
Figure 6
Table 5 from Approved Document L
14
Figure 7
Table 6 from Approved Document L
15
Figure 8
NZ building code system and proposed energy efficiency implementation
18
Figure 9
Average annual number and floor area of new buildings 1970-1993
19
Figure 10 Extract from NZS 4218 - Energy efficiency housing and
10
20
small building envelope
Figure 11 Extract from NZS 4243 - Energy efficiency large buildings
21
Figure 12 Summary of energy codes adopted by the States of the USA
25
Figure 13 USA Model Energy Code
27
Figure 14 Example of a prescriptive package table
28
Figure 15 USA residential building compliance routes
30
Figure 16 Extract from IECC 1998 of a table for the prescriptive
32
building envelope requirements
Figure 17 Overall picture of achieving compliance in ASHRAE/IES Energy Code
33
Figure 18 Extract from ASHRAE/IES 90.1 of an Alternative Component Package Table
34
Figure 19 Extract from ASHRAE/IES 90.1 of a table for envelope requirements
36
Figure 20 California Energy Code compliance routes for non-residential,
39
high-rise residential, and hotel/motel buildings
vi
Figure 21 Prescriptive requirements for non-residential buildings
40
Figure 22 California Energy Code compliance routes for low-rise residential buildings
41
Figure 23 Prescriptive requirements for residential buildings
43
Figure 24 Flow chart for compliance
45
Figure 25 Status of energy codes adopted in the Provinces of Canada
51
Figure 26 National Model Energy Code compliance routes.
52
Figure 27 Example of prescriptive tables in the MNECH
54
Figure 28 Example of prescriptive tables in the MNECB for building envelopes
56
Figure 29 Example of prescriptive tables in the MNECB for glazed areas
57
I N T E R N AT I O N A L
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
Figure 30 Table 9.25.2.1 for the minimum thermal resistance insulation
59
required to building elements
Figure 31 Table 9.38.3.1 for the minimum thermal resistance insulation
60
required to building elements
Figure 32 BCA building compliance routes
64
Figure 33 Table F6 of ACT Appendix
65
Figure 34 Extract from Table 2.1 from AS 2627.1
66
Figure 35 Extract from Table 2.2 from AS 2627.1
67
Figure 36 Extract from AS 2627.1 for roofs/ceilings
67
Figure 37 Extract from AS 2627.1 for walls
67
Figure 38 Table 1 from Minister’s Guideline SA 2.1
68
Figure 39 Table 2 from Minister’s Guideline SA 2.1
68
Figure 40 Table F6.1 of the Victorian Appendix
69
Figure 41 Table F6.2 of the Victorian Appendix
69
A B B R E V I AT I O N S
vii
ABCB
Australian Building Codes Board
ACT
Australian Capital Territory
ACTHERS
ACT House Energy Rating Scheme
AFUE
Annual Fuel Utilisation Efficiency
AGO
Australian Greenhouse Office
ALF
Annual Loss Factor
ASHRAE
American Society of Heating Refrigeration and Air-conditioning Engineers
ACP
Alternative Component Package
BCA
Building Code of Australia
BECON
Building Energy Cost Budget Method
BESTEST
Building Energy Simulation Test
BIA
Building Industry Association
BPI
Building Performance Index
CEC
California Energy Code
CIBSE
Chartered Institution of Building Services Engineers
DD
Degree-days
DECON
Design Energy Consumption
DECOS
Design Energy Cost
DETR
The Department of the Environment, Transport and the Regions
DTS
Deemed-to-Satisfy
ECB
Energy Cost Budget
HUD
USA Department of Housing and Urban Development
HVAC
Heating, ventilating and air-conditioning
IECC
International Energy Conservation Code
IES
Illuminating Engineering Society of North America
I N T E R N AT I O N A L
ILPA
IRCC
kWh
m2
MNECH
MNECB
MPS
NatHERS
NZ
NZBC
OTTV
RIS
SAP
SEER
SWH
UK
USA
U-value
FirstRate
W/m2
WWR
viii
S U R V E Y
O F
B U I L D I N G
E N E R G Y
Interior Lighting Power Allowance
Inter-Jurisdictional Regulatory Collaboration Committee
Kilowatt hour
Square metres
Model National Energy Code for Houses
Model National Energy Code for Buildings
USA Minimum Property Standards
Nationwide House Energy Rating Scheme
New Zealand
New Zealand Building Code
Overall thermal transmittance value
Regulatory Impact Statement
Standard Assessment Procedure
Seasonal Energy Efficiency Ratio
Service water heaters
United Kingdom
United States of America
Thermal transmittance
Victorian House Energy Rating Scheme
Watts per square metres
Window to wall ratio
C O D E S
SECTION ONE
INTRODUCTION
I N T E R N AT I O N A L
SECTION 1
S U R V E Y
B U I L D I N G
E N E R G Y
C O D E S
INTRODUCTION
With the successful conclusion of the international conference
As part of the introduction of mandatory minimum energy
on greenhouse gases in Kyoto, Japan, in December 1997, a
efficiency provisions into the Building Code of Australia,
post-2000 global response is currently being put in place to
preliminary studies have been commissioned by the Australian
help address the threat of climate change. The Kyoto Protocol
Greenhouse Office to research the parameters and implications
to the Framework Convention on Climate Change represented
of such a task. A recent scoping study has been completed
a significant advance for the global environment. For the
by CSIRO on "Minimum Energy Performance Requirements
first time developed countries have made legally binding
for Incorporation into the Building Code of Australia".
commitments to reduce their greenhouse gas emissions
and address the threat of climate change.
In line with this study, the AGO has further commissioned the
ABCB Office to prepare this study of the energy efficiency
Australia played an active role in the negotiations and
provisions contained in overseas building codes. It is intended
achieved an outcome that allows us to assume emission
to provide an insight into the different provisions applied to the
limitation commitments in line with the unique features of
various buildings around the world in the context of each
our economy. Improving energy efficiency is one of the most
country's regulatory system.
cost-effective ways of reducing greenhouse gas emissions
both in Australia and around the world. Energy use is the
dominant source of Australian greenhouse gas emissions
with 55 per cent of total emissions generated by the
combustion of fuels to provide stationary energy. Predictions
show that these emissions are expected to grow by over
28 per cent between 1990 and 2010.
Following wide consultation between the Federal Government
and the building industry, it was announced on 24 March 1999
that the Ministerial Council on the Greenhouse reached a
landmark agreement on a comprehensive strategy aimed
at making our homes and commercial buildings more energy
efficient. This agreement featured a two pronged strategy
that will see the introduction of mandatory minimum energy
performance requirements through the Building Code of
Australia while encouraging and supporting voluntary
best practice initiatives.
2
O F
With this knowledge, and the recommendations contained in
the Scoping Study carried out by the CSIRO for the AGO,
stakeholders will be in a position to provide informed comment
on possible mandatory energy efficiency measures.
SECTION TWO
STUDY SCOPE AND METHODOLOGY
I N T E R N AT I O N A L
SECTION 2
2.1
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
STUDY SCOPE AND METHODOLOGY
Scope
2.2
Methodology
This study is to assess the suitability of overseas
The building regulations of many countries already contain
regulatory approaches and to assist in the development and
environmental protection, energy efficiency or fuel conservation
implementation of energy related building code requirements
measures. It would be too onerous to study all countries that
for the Building Code of Australia.
have energy efficiency provisions within their built environment.
In particular, this study is to determine what energy efficiency,
greenhouse gas reduction or fuel conservation measures
exist, or are being considered for inclusion, in overseas and
Australian building regulations and codes. The outcomes
of this report will be used as an information source when
Rather this study concentrates on countries with similar
regulatory, climatic or socio-economic characteristics
to Australia.
Countries considered in the study were:
■
Australia (South Australia, Victoria and ACT);
inclusion in the Building Code of Australia.
■
Canada (including Ontario);
The brief for this study requires that the following aspects
■
New Zealand;
■
Singapore;
■
United Kingdom; and the
■
United States of America (including California and Hawaii).
determining what measures should be considered for
be considered and, where relevant, be reported upon:
■
the objective of the provisions;
■
the stringency measures and levels;
■
the overall regulatory framework these provisions
Some countries, like the United Kingdom and New Zealand,
operate under;
have a national code that is adopted throughout the country
■
the philosophy followed and scope covered;
as the single mandatory code for compliance. Other countries,
■
any performance measures, qualitative and quantitative;
■
any assumptions, such as the use of "standard" buildings;
adopt as a whole, in part, or not at all.
■
any verification methods;
An example of this is Canada that has a national model energy
■
any prescriptive methodologies and provisions;
■
the application and any limitations for building types,
a model code exists. For example, in the case of Canada,
uses, etc;
the Province of Ontario code is reviewed.
■
how ventilated or "free running houses" are dealt with;
Similarly, the USA has 50 states and three code writing
■
the extent of climatic zoning;
bodies. The current main code and the future code have
■
any consideration of fuel type and cost;
codes for the State of California and Hawaii which both have
■
any consideration of construction costs; and
separate energy codes. These States were also selected
■
any use of modelling software.
such as United States of America (USA) and Canada, have a
national model code that individual States or Provinces may
code but not all Provinces have adopted the code. For this
reason, this study is extended to include a typical code where
been discussed in this report as well as the energy efficiency
because of similarities of climate, building environment and
It should be emphasised that this is a survey of current
practices. For example, it is known that Canada, the USA
and other countries are moving to a performance based
building code which will mean significant change that could,
in turn, effect energy efficiency provisions. The Kyoto Protocol
may also have prompted countries to commence reviewing
their requirements.
4
socio-economic conditions with Australia.
I N T E R N AT I O N A L
S U R V E Y
There are also some energy efficiency provisions already
appended to the Building Code of Australia. These provisions
only apply in the Australian Capital Territory (ACT), South
Australia and Victoria. Further energy efficiency provisions
are currently proposed in other States either through a State
model code, through planning legislation or other local
government initiatives. Due to the varying requirements of
these initiatives and their narrow geographical focus, only
the provisions of South Australia, Victoria and the ACT will
be discussed.
The Australian Building Codes Board is an active member
of the Inter-Jurisdictional Regulatory Collaboration Committee
(IRCC) along with the USA, Canada, UK, Sweden, Norway,
New Zealand and Japan. The purpose of the IRCC is to
advance, at an international level, framework, guidance,
and support documents on construction-related regulatory
environment issues relative to the development, implementation,
and support of performance-based regulatory systems. With
such close links, the ABCB has access to many international
building control officials.
Throughout the preparation of this report, there has been
close liaison with building officials from other countries to
ensure the accuracy of the material. These people have
contributed to the accuracy of the technical content of this
report and their efforts are appreciated. They are listed
in Appendix A.
5
O F
B U I L D I N G
E N E R G Y
C O D E S
SECTION THREE
TERMINOLOGY
I N T E R N AT I O N A L
SECTION 3
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
TERMINOLOGY
In many cases, terms used by building officials in Australia
Appendix for their specific energy efficiency provisions.
may be used in a different context to how they are used
Performance Requirement Vic FP6.1 states-
overseas or how they are used by people of different
professional backgrounds. The target audience of this report
may include people from Government Departments, technical
experts, hands-on builders, building regulators, manufacturers,
"A building must have an adequate level of thermal
performance to ensure efficient use of energy for
internal heating and cooling".
property owners, etc. both within Australia and internationally.
Some countries like New Zealand have quantitative
Due to this diverse range of possible readers, it is necessary
performance requirements. These specify a certain level or
to explain certain terms used in the report so that the reader
quantity that the performance of the building or element must
can better understand the context in which it is used.
achieve. For example the NZ Performance Requirement
The following are some terms that will need clarifying.
H1.3.1 states'The building envelope shall be constructed to ensure
3.1
Performance Requirements
that the building performance index shall not exceed
0.13 kWh."
The term "Performance" is used throughout the world in a
regulatory sense yet has many meanings depending on the
In this case, a quantitative measure (0.13 kWh) has been
country and its inherent building environment. Performance
applied to the Performance Requirement.
in the Australian context is represented by the performance
In other countries, the term performance has been used
hierarchy contained within the BCA.
to describe a means of achieving energy efficiency. In the
The performance hierarchy in the BCA is represented by
Australian context, this is not performance but a Deemed-to-
the Objectives, Functional Statements and Performance
Satisfy (DTS) Provision. Generally, it is a prescribed procedure
Requirements.
that utilises or measures the performance of the building,
usually via an annual cost analysis or a heat loss/gain analysis.
The Objective indicates what the general community
expects with regard safety, health and amenity. The Functional
If this prescribed procedure is followed and the building
achieves the required outcome, it is deemed to comply.
Statements describe how a building contributes to achieving
this Objective. The Objective and Functional Statement are
Therefore, although a performance method is available in
not mandatory and are only included to explain the basis
a particular code, this would be regarded as a prescriptive
of the Performance Requirements.
approach, or possibly a verification method, in the Australian
context.
The Performance Requirement is the mandatory component
of the BCA and is defined as:
The table in Appendix E summarises the applicable code
requirements for each country. One column within the table
"a requirement which states the level of performance
which a Building Solution must meet."
hierarchy. This means a performance hierarchy in the
The BCA Performance Requirements are deliberately written in
Australian context eg. Objective, Functional Statement
a qualitative manner. Qualitative, meaning that they must have
and Performance Requirements.
certain attributes or qualities to achieve a certain level of
performance. An example of this is contained in the Victorian
7
indicates whether a country's energy code has a performance
I N T E R N AT I O N A L
3.2
S U R V E Y
Alternative Solution
B U I L D I N G
3.3
E N E R G Y
C O D E S
Ventilated Buildings
The term Alternative Solution is also mentioned throughout
The term "ventilated buildings" in this report, means the
this report. Again, this is discussed in the Australian context.
method of controlling the environment in a building without
The definition of an Alternative Solution in the BCA:
using heating or refrigerated air-conditioning. It includes natural
"means a Building Solution which complies with the
Performance Requirements other than by reason of
satisfying the DTS Provisions."
ventilation, fan assisted ventilation and evaporative cooling. It
is some times called passive comfort conditioning or a building
may be described as "free running". It is different to the current
BCA ventilation requirements, which are the minimum amount
An Alternative Solution is any solution that complies with the
of outside air that must be introduced for health and odour
Performance Requirements other than the standard
control.
prescriptive provisions. An example of this, apart from in the
Australian context, is in the UK where Approved Document L
is the recommended prescriptive method. However the UK
Building Regulations allowed any "other method" to be used
so long as the building is deemed to be "energy efficient". This
"other method" would be considered an Alternative Solution.
8
O F
SECTION FOUR
UNITED KINGDOM
I N T E R N AT I O N A L
SECTION 4
4.1
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
UNITED KINGDOM
Regulatory Framework
In England and Wales, the 1991 Building Regulations provide
for the health and safety of people in and around buildings
by setting functional requirements for building design and
construction. In addition, these regulations promote energy
the Building Regulations by following the guidance in
Document L or by an Alternative Solution. The requirements
generally cover limiting heat loss through:
■
the fabric of the building;
■
the control of space heating and domestic hot water
efficiency in buildings through Part L, Schedule 1 titled
systems;
Conservation of Fuel and Power.
■
hot water pipes and hot air ducts; and
■
the control of lighting (lamp efficiency) in non-domestic
Energy efficiency requirements were first introduced into
the Building Regulations in 1974 in response to the Arab oil
embargo with the aim of conservation of fuel stocks. A new
buildings having a lit area more than 100 m2.
Building Act was introduced in 1984 that changed this aim
Similar technical provisions are enforced in Scotland and
to the conservation of fuel and power. The current Building
Northern Ireland through separate legislation but for the
Regulations, 1991 have the explicit aim of controlling CO2
purposes of this study, Approved Document L will be
emissions from buildings.
reviewed as being indicative of the energy efficiency
To assist builders and developers to comply with the Building
requirements for the UK.
Regulations, the Department of the Environment, Transport
In the Australian context, Approved Document L is essentially
and the Regions (DETR) has published a series of "Approved
a prescriptive code. However, through the Building Regulations,
Documents". These provide guidance on ways the legal
1991, a builder, owner or developer may show compliance via
requirements can be met. They are not mandatory, but can
an Alternative Solution, subject to acceptance by the Approval
be accepted as complying with the Building Regulations.
Authority. This would suggest that the energy efficiency
The relevant Approved Document for energy efficiency is
Approved Document L. - Conservation of fuel and power.
This document repeats the legal requirements set out in
Schedule 1 to the Regulations, gives guidance on what the
requirements within the UK are performance based. The
means of assessing and accepting an Alternative Solution,
as well as how often this approach is used, is not known,
but the option is available.
Secretary of State considers how a building should perform
The building regulations have an overlying Performance
to be considered energy efficient, and then goes on to offer
Requirement that is repeated in Approved Document L.
some ways of showing compliance. A builder, owner or
It can be used as guidance in accepting Alternative
developer may choose to show compliance with
Solutions. See figure 1.
Figure 1
Extract from Approved Document L - Performance requirements L1
Requirements
Limits on application
Conservation of fuel and power
L1. Reasonable provision shall be made for the conservation of fuel and
Requirements L1(a), (b), (c)
power in buildings by:
and (d) apply only to -
(a) limiting the heat loss through the fabric of the building;
(a) dwellings;
(b) controlling the operation of the space heating and hot water systems;
(b) other buildings whose floor area exceeds 30 m2.
(c) limiting the heat loss from hot water vessels and hot water service pipework:
(d) limiting the heat loss from hot water pipes and hot air ducts used for space heating;
10
(e) installing in buildings artificial lighting systems which are designed and constructed
Requirement L1(e) applies only within buildings where
to use no more fuel and power than is reasonable in the circumstances and making
more than 100 m2 of floor area is to be provided with artificial
reasonable provision for controlling such systems.
lighting and does not apply within dwellings.
I N T E R N AT I O N A L
4.2
S U R V E Y
O F
B U I L D I N G
Scope
Figure 2
E N E R G Y
C O D E S
UK Energy Code compliance
routes for dwellings
As shown in the "Limits on application", the requirements
of L1 only apply to:
■
dwellings; and
■
other buildings where the floor area does not exceed
PERFORMANCE REQUIREMENT L1
30m2.
A dwelling is a building designed for the residential use of a
family or other domestic household. It includes attached and
detached housings and individual units of multi-residential
PRESCRIPTIVE PROVISIONS
apartments but not the whole building. It does not include
accommodation for the elderly, hostels, hotels/motels, etc.
Approved Document L does not apply to:
■
small extensions (not exceeding 10m2); or
■
a commercial or industrial building with no heating or a low
ELEMENTAL
METHOD
level of heating (output of the space heating system does
TARGET
U-VALUE
METHOD
ENERGY
RATING
METHOD
not exceed 50W/m2).
It also has minimal requirements for conservatories not forming
an integral part of a new dwelling.
4.3
Categories
The technical solutions in Approved Document L that are
Different standard U-values are given for building elements
depending on the completed dwellings estimated Standard
deemed to meet the Performance Requirement L1 are broken
Assessment Procedure (SAP) rating. Refer below for details
down into dwellings and buildings other than dwellings.
on the method of obtaining an SAP rating. The different SAP
These will be considered separately.
ratings are categorised into:
4.4
■
SAP rating of 60 or less; or
■
SAP rating of over 60.
Dwellings
To meet the requirements for fabric performance a designer
may follow one of the three available methods specified in the
SAP rating
Approved Document L. See figure 2. These three methods are
used to demonstrate how heat loss through the building fabric
As part of the administrative requirements of Regulation 14A
is limited. They are:
in the Building Regulations, builders, developers or owners
have to calculate the SAP Rating for every new dwelling.
■
the elemental method;
■
the target U-value method; and
separate from compliance with the technical provisions in
■
the energy Rating method.
Part L of Schedule 1. The administrative requirement states
This is an administrative requirement in Regulation 14A
that a SAP Rating must be submitted at the completion of
4.4.1 Elemental Method
the building works. This was a new initiative introduced in
The elemental method requires that certain building elements
1994 aimed at making annual energy cost information
such as roofs, walls, floors, windows, doors etc. achieve the
more accessible to prospective purchasers and tenants
minimum thermal transmittance (U-value) as specified in Table
1 of Approved Document L. See Figure 3 for an extract of
the table.
11
of new dwellings.
I N T E R N AT I O N A L
Figure 3
S U R V E Y
Table 1 from Approved Document L
O F
B U I L D I N G
E N E R G Y
C O D E S
There is also a standard requirement for the average
performance of windows, doors and roof lights in relation to
Table 1 Standard U-values (W/m2K) for dwellings
their area, not to exceed a certain percentage of the floor area
For SAP Energy Ratings of:
60 or less
over 60
Element
(a)
(b)
Roofs (1)
0.2
0.25 (2)
of the building. For example, the total area of the windows,
doorways and roof lights should not exceed 22.5% of the floor
area of the building if the average U-value for windows, door
and roof lights combined is 3.3 W/m2K .
Exposed walls
0.45
0.45
Note that there is an alternative prescriptive requirement for
Exposed floors and ground floors
0 35
0.45
floors under Appendix C. This is a calculation using a graph
Semi-exposed walls and floors
0.6
0.6
where the floor may be sufficiently large (width and length)
Windows, doors and rooflights
3.0
3.3
not to warrant any further insulation.
Notes
1.
2.
Any part of a roof having a pitch of 70° or more may have the same
4.4.2 Target U-value Method
U-value as a wall.
This method requires that both a target U-value, and an
For a flat roof or the sloping parts of a room-in-the roof construction
average U-value, be calculated for a subject building. If the
it will be acceptable if a U-value of 0.35 W/m2K is achieved.
average U-value of the proposed dwelling does not exceed
the target U-value, then compliance is shown.
A target U-value is calculated using a formula that takes into
account the floor area of the building in relation to the total
area of exposed elements. There are two different formulas
The "Government's Standard Assessment Procedure for
Energy Rating of Dwellings - 1998 Edition" contains the
procedure for providing an energy rating – a SAP Rating.
The analysis takes into account the building’s dimensions,
for obtaining the target U-value depending on whether the
dwelling has a SAP rating of less than or equal to 60, or a
SAP rating for over 60.
fabric thermal resistance, ventilation, heat losses and gains,
The average U-value is calculated by summing the proposed
water heating, weather conditions, space heating and fuel
U-values for each exposed surface and calculating the
costs. The SAP delivers a rating on a scale of 1 (worst) to
average U-value over the sum of the exposed surface areas.
100 (best).
With this administrative requirement to calculate a SAP
4.4.3 Energy Rating Method
Rating in place, it was also recognised as a way of showing
The previous two methods only took into account the
compliance with the technical requirements in Part L.
envelope components. The energy rating method is a holistic
However, applications for approval are made at submission
approach, which also takes into account ventilation rates,
stage, not when the dwelling is completed, so the builder has
service water heating (SWH), internal heat gains, solar gains
to determine an approximate rating for the building to use
and the cost of fuels used.
the Elemental Method. Appendix G in Approved Document L
provides some examples of dwellings and their SAP Ratings
to give builders and building control inspectors an initial feel
of what to expect.
This method requires that a SAP rating be calculated in
accordance with the Government's standard assessment
procedure for energy rating of dwellings. This calculated
SAP rating cannot be less than the SAP ratings outlined in
Once a SAP rating is calculated, a designer can obtain the
U-values for a building element from Table 1. After the Uvalues are determined, a designer can refer to Appendix, A
which describes construction systems that are deemed to
12
Table 4 of Approved Document L. See Figure 4. The SAP
ratings in Table 4 are default ratings for houses with a range
of floor areas.
provide the required U-values. These systems usually involve
As stated previously, the SAP rating is an energy rating taking
typical construction methods (brick veneer, cavity brick
into account the calculated annual energy cost for space and
construction, etc.) with certain types and thickness of
water heating. Under the Elemental Method, SAP ratings of
insulation. However, these tables are conservative and
around 65 to 75 are achieved using the specified U-values of
builders usually use materials producers’ catalogue data
the external envelope components and a typical gas central
(eg. Owens Corning).
heating system and service water heating (90% of UK market).
I N T E R N AT I O N A L
Figure 4
S U R V E Y
Table 4 from Approved Document L
O F
B U I L D I N G
E N E R G Y
C O D E S
4.4.4 General requirements for dwellings
There are further prescriptive provisions contained in Approved
SAP Energy Ratings to demonstrate compliance
Document L for dwellings, regardless of which method is used
Dwelling floor area (m2)
to meet the Performance Requirement. These include:
SAP Energy Rating
80 or less
80
more than 80 up to 90
81
more than 90 up to 100
82
more than 100 up to 110
83
more than 110 up to 120
84
more than 120
85
Thermal bridging around openings
Satisfactory methods for bridging are specified
diagrammatically as well as an alternative calculation
method being provided.
Limiting infiltration
A series of sealing methods that are deemed to
meet the requirements are specified and shown
diagrammatically. Further guidance in another report
For oil based systems the same dwelling might have a SAP
is also referenced.
Rating 10 points higher because of the price advantage oil
Space heating system controls
had at the time the cost data table was produced. For direct
Zoning, operation time and boiler management
on-peak electric heating, the same dwelling could have a SAP
Rating of around 50. There is no minimum SAP Rating – only
controls are all required so that energy is not
used unnecessarily.
a requirement to produce one so that a prospective purchaser
HWS system controls
can see it and consider it. Under the Energy Rating Method,
A level of efficiency is specified for heat exchangers
the SAP energy rating required ranges between 80 and 85.
and a thermostat and timer are required so that water
is not heated unnecessarily. There are also alternative
The reason for the different SAP ratings in the Elemental
approaches that can be used to meet the requirements
Method and the Energy Rating Method is that the Elemental
for space heating and hot water. These approaches
Method is merely one way of showing that the fabric thermal
consist of following other British Standards that refer to
resistance is reasonable. The builder then has to show
compliance of thermal bridging, air-tightness, space heating
and hot water controls.
controls, or by using authoritative design specifications
recognised by the heating fuel supply companies.
Insulation of vessels, pipes and ducts
An approved insulation method is given for
With the Energy Rating Method, a user has to show that
hot water vessels. Alternatively, following another British
acceptable provisions against thermal bridging have been
Standard can satisfy this requirement. Specifications
made, that the limiting U-values have not been exceeded
for insulation of pipes and ducts are also given and
and, by a combination of fabric and central heating and
they, in turn, reference British Standards.
service water heating performance, the minimum SAP
Conservatories
Rating of 80 to 85 has been achieved.
If a conservatory is connected as an integral part
of a new dwelling it should be treated as a part of the
dwelling for the purposes of glazing allowance, target
U-value etc. However, it should also be separated
from the dwelling (a definition of adequate separation
is given) and any fixed heating should be separately
controlled.
13
I N T E R N AT I O N A L
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
4.5.1 Elemental Method
Material alterations
If the proposed work includes altering elements of the
The Elemental Method for buildings other than dwellings is the
fabric then some improvement is required dependent
same as for dwellings with the exception that there is no SAP
upon the circumstances in the particular case. When
rating calculation. Figure 6 is Table 5 of Approved Document L
heating and HWS systems are to be altered, provisions
and shows the standard U-values for certain elements.
should be the same as for new installations although
There are also prescriptive provisions for windows, doors and
again, it will depend on the circumstances in the
roof lights. Their area is not to exceed a certain percentage of
particular case.
the wall area of the building. Note that this is different to
dwellings where floor area is the basis. See Figure 7. For
Material changes of use
If the building is undergoing a change of use,
elements may not need to be brought up to current
code requirements unless they are being replaced as
part of material alterations.
example, the total area of the windows and doorways cannot
exceed 40% of the wall area of a typical office building if the
average U-value of all the glazing and personnel doors is no
more than 3.3 W/m2K.
4.5.2 Calculation Method
Under the Calculation Method, the rate of heat loss is
4.5
Buildings Other Than Dwellings
calculated for a 'notional' building that complies with the
As with dwellings, to meet the performance, a designer
Elemental Method and is the same size and shape as the
needs to comply with only one of the three available methods
proposed building. The calculation using the notional building
specified in Approved Document L to demonstrated how heat
uses default area percentages of windows, doors and roof-
loss through the building fabric must be limited. They are
lights to calculates the rate of heat loss as per the Elemental
shown in Figure 5 and are:
Method. The rate of heat loss is then calculated for the
proposed building taking into account the actual areas.
■
the Elemental Method;
■
the Calculation Method; and
■
the Energy Use Method.
Figure 5
To comply with the Calculation Method the proposed
building's rate of heat loss cannot exceed the notional
building's rate of heat loss.
UK Energy Code compliance routes
for buildings other than dwellings
Figure 6
Table 5 from Approved Document L
Table 5 Standard U-values (W/m2K) for buildings
other than dwellings
Element
PERFORMANCE REQUIREMENT L1
PRESCRIPTIVE PROVISIONS
Roofs (1)
U-value
0.25 (2)
Exposed walls
0.45
Exposed floors and ground floors
0.45
Semi-exposed walls and floors
0.6
Windows, personnel doors and rooflights
3.3
Vehicle access and similar large doors
0.7
Notes
1.
Any part of a roof having a pitch of 70° or more may have the
same U-value as a wall.
ELEMENTAL
METHOD
CALCULATION
METHOD
ENERGY
USE METHOD
2.
For a flat roof or insulated sloping roof with no loft space it will be
acceptable if a U-value of 0.35 W/m2K is achieved for residential
buildings or 0.45 W/m2K for other buildings.
14
I N T E R N AT I O N A L
Figure 7
S U R V E Y
Table 6 from Approved Document L
O F
B U I L D I N G
E N E R G Y
C O D E S
Naturally ventilated buildings
For naturally ventilated buildings, an acceptable method of
Table 6 Basic allowance for windows, doors and rooflights for
buildings other than dwellings
Building type
Windows and doors(1)
Residential buildings (2)
Rooflights
30%
Places of assembly,
20% of
40% (3)
offices and shops
roof area
demonstrating compliance is given in the Chartered Institution
of Building Services Engineers (CIBSE) publication Building
Energy Code 1981 Part 2a.
4.5.4 General requirements for
buildings other than dwellings
Similar to dwellings, there are further prescriptive provisions
for buildings other than dwellings. Key provisions are
Industrial and storage
tabulated below.
buildings
15%
Vehicle access doors
(all building types)
As required
Thermal bridging around openings
Similar provisions as for dwellings.
Notes
1.
Percentage of exposed wall area.
Limiting infiltration
2.
Residential buildings (other than dwellings) means buildings in which
Similar provisions as for dwellings.
people temporarily or permanently reside: for example, institutions, hotels
Space heating system controls
and boarding houses.
Similar provisions as for dwellings although outside
See paragraph 2.3 regarding exclusions.
compensator control and optimum start control are
3.
considered reasonable if the installed heating capacity
exceeds 100 kW.
HWS system controls
Similar provisions as for dwellings for small scale –
An example of this method is if the proposed building's total
area of windows and doors is 50% of the wall perimeter. It has
no roof lights. As shown in Table 6 (see Figure 7) a building to
comply with the Elemental Method cannot have windows and
doorways exceeding 40% of the floor area of the building.
The notional building will assume a window area of 40% and a
roof light area of 20%. Broadly speaking, the heat loss through
the default areas of openings (totalling 60%) in the notional
building will more than likely outweigh the extra 15% window
area of the proposed building which would have not been
permitted under the Elemental Method.
4.5.3 Energy Use Method
This is similar to the Calculation Method, except the
Calculation Method focuses on fabric resistance whilst the
Energy Use Method focuses on annual energy consumption.
The Energy Use Method involves calculating the overall annual
energy consumption of the proposed building and comparing
it with the likely annual energy consumption of a similar
building that complies with the Elemental Method.
15
The main difference between this and the Calculation Method
is that solar and internal heat gains are taken into account.
Once again, this method can exceed the limitations within
the Elemental Method by trading off other energy efficiency
provisions although the limits on thermal bridging and U-values
cannot be traded. The aim is to broadly get the same
performance while allowing greater design flexibility.
reference to British Standards for larger.
Insulation of vessels, pipes and ducts
Similar provisions as for dwellings.
Lighting
A minimum efficiencies for 95% of the installed lamps
are given in a tabulated form. Display and emergency
lighting are excluded. Local switches are required
that are easily accessible to occupants or automatic
switches that sense when there is adequate daylight
or no occupants within the room.
Alternatively, there is a calculation procedure available
and a performance target of 50 lumens per watt.
Maximising the use of daylight or photoelectric
switches is another way of meeting the requirements.
Compliance can also be achieved by following the
CIBSE Publication Code for Interior Lighting provided
the design performs no worse than the designs
specified in the Approved Document.
Material alterations
Similar provisions as for dwellings.
Material changes of use
Similar provisions as for dwellings.
SECTION FIVE
NEW ZEALAND
I N T E R N AT I O N A L
SECTION 5
5.1
S U R V E Y
B U I L D I N G
E N E R G Y
C O D E S
NEW ZEALAND
Regulatory Framework
The energy efficiency requirements for buildings are contained
in the New Zealand Building Code (NZBC) which is a statutory
requirement because it is part of the Building Regulations
1992. The current requirements (at February 2000) were
introduced in 1978 for houses and 1993 for commercial
and public buildings. These initial requirements are reasonably
brief and have a relatively narrow scope.
The Building Industry Authority (BIA), which is the equivalent
of the ABCB, completed a review of the energy efficiency
requirements in 1996. This review led to the development
and publication of three new energy efficiency standards
by Standards New Zealand. They broaden the scope and
provide requirements that are more detailed.
The recommendations of the BIA were forwarded onto the
Government and approved in October 1999, but with the
change of Government, there has been a delay in their
implementation.
This report comments briefly on the current requirements
and concentrates on the proposed new ones.
5.2
O F
Current Requirements
5.2.1 Scope
The current requirements are split into the following categories:
The Verification Method to calculate the BPI is to use a
procedure contained in the Annual Loss Factor (ALF) Manual.
The ALF method uses the building envelope R-values, the
window solar gains and the heat loss of the building depending
on the climate zone, the house configuration and area. The
ALF method can be manually calculated or calculated using
a software package.
ALF is similar in concept to FirstRate or ACTHERS (both of
which are only available in computer form), in that it is built
from a large number of computer simulations on a limited
range of house types. One consequential limitation for ALF
is that it deals best with standard house types, and it is not
suitable for specialist passive solar designs (eg. use of
Trombe walls).
The Acceptable Solution is compliance to Clause 2 of NZS
4218P:1977. This basically provides different combinations
of R-values for ceilings, walls and floors in a tabular format.
5.2.3 Buildings other than houses
For buildings other than houses, compliance is demonstrated
by a Verification Method based on NZS 4220:1982. The
Verification Method gives only guidance to meeting the
Functional Requirements (which are normally measured
against the Performance Requirement). This standard covers
heat losses and gains through the building envelope, air
■
Housing
tightness, space heating, building services such as hot water
■
Other buildings
and lighting, utilising of waste heat from internal processes
and control systems for heating and ventilation.
Performance requirements are provided for both these
categories with the performance for housing being quantitative
whilst for other buildings being qualitative. A mandatory
guideline (Verification Method) provides the mechanism for
demonstrating compliance with the performance stated in
the Code, but a prescriptive method (Acceptable Solution)
is only provided for housing.
The Performance Requirements for buildings other houses
will be more explicitly catered for by the new proposed
system discussed hereafter.
5.3
Proposed Future Requirements
The proposed new system for energy efficiency measures
5.2.2 Housing
within the New Zealand regulatory system is represented in
There are two methods of compliance, namely:
Figure 8.
■
compliance with the acceptable solution; or
■
demonstrate compliance of an alternative solution
using the Verification Method
There are likely to be two methods for complying with the
future energy efficiency requirements of the NZBC. They are:
■
at the code compliance authority’s discretion; and
The quantitative performance for housing states that-
17
"The building envelope shall be constructed to
ensure that the Building Performance Index (BPI)
shall not exceed 0.13 kWh."
using an Alternative Solution, which may be acceptable
■
complying with the ‘Approved Document’, which can be
achieved by using an Acceptable Solution or by following
the Verification Method.
I N T E R N AT I O N A L
Figure 8
S U R V E Y
NZ building code system and proposed
energy efficiency implementation
O F
B U I L D I N G
E N E R G Y
C O D E S
The two different zone approaches result in similar
requirements for much of the country, but the Standards use
zones based on territorial local authority boundaries, and can
therefore be used most readily by designers or builders not
wishing to undertake any calculation.
Clause H1
5.3.1 Alternative solution
An Alternative Solution is the using of any other material,
method, system or design that, with suitable justification
Approved
Documents
Alternative
Solutions
can be accepted by the Territorial Authority, as complying
with the Performance Requirements of the NZBC.
There will be little data on the viability of the use of Alternative
Solutions until the proposed changes have been in force for
a period of time. True performance Alternative Solutions may
Verification
Method
Acceptable
Solutions
not be such an attractive option since the solutions in the
DTS Provisions are relatively effective, easy to use and readily
accepted. Alternative Solutions also need to be justified for
use with the Approval Authority, which may be cumbersome.
Alternative Solutions are more likely to be used on a unique
NZS 4218 - 1996
Housing & Small
Buildings
NZS 4243 - 1996
Large Buildings
NZS 4306 - 1996
Domestic
Hot Water
type of building where the solution could be shown to be more
efficient, meets individual client needs or is more cost effective.
5.3.2 Compliance with the approved documents
Compliance with the Approved Document, is compliance with
the NZBC. The actual code provides two routes for compliance.
One is a Verification Method measured against the performance
and the other is the prescriptive requirements of referenced
documents, namely the following New Zealand Standards:
Climate zones
For the purposes of the future expected requirements the
Acceptable Solutions based on NZS 4218:1996 or NZS
■
NZS 4218:1996 Housing and Small Buildings;
■
NZS 4243:1996 Large Buildings; and
■
NZS 4305: 1996 Domestic Hot Water.
4243:1996 use three climate zones to cover New Zealand.
For houses and small buildings climate zones 1 and 2 are
grouped, whilst for large buildings zones 2 and 3 are grouped,
5.3.2.1 Verification Method
and thus there are essentially only two climate zones used for
either category of building.
The proposed Verification Method for housing is still based
on the ALF Method, which utilises the BPI.
If the Verification Method is used (as distinct from the
modelling or calculation methods in NZS 4218:1996 or NZS
The BPI and the Acceptable Solutions were developed as
4243:1996), then two climate zones (‘warm’ and cool’) based
the result of a cost benefit analysis of the extra capital cost
on degree-days (DD) are used. Degree-days are a means of
of insulation, etc. against the expected savings in energy
expressing the severity of the climate in terms of the frequence
costs. Generally, the payback period would be eight to ten
that the outside temperature is less than 15.5 degrees Celsius.
years (based on 8% owner discount rate and 5% national
On one particularly cold day there might be six or seven DD
discount rate).
recorded. It is a good measure of how cold a particular area
18
is over the whole winter period, and so is a measure of how
The analysis also assumes that the building has a life of
much heating energy will be needed to maintain comfortable
50 years, of which the owner would own it for 20 years.
internal temperatures in a building. For example, Christchurch
Therefore, the measures are based on national energy costs
has approximately 950 DD. The NZ Meteorological Service
and benefits for the owners, but not greenhouse effects,
data covers approximately 80 locations.
sustainability, reduction of oil imports, or other criteria.
I N T E R N AT I O N A L
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
5.3.3 NZS 4218 - 1996 housing and small buildings
5.3.2.2 Prescriptive requirements
of referenced documents
This standard specifically deals with housing and small
Research has been carried out on buildings constructed
buildings less than 300m2. Housing by definition includes:
over the period 1970 to 1993, examining type, floor area and
number of storeys. By far the greatest number of buildings
■
were those in the small floor area category (< 300m2) and
detached dwellings including a single household, boarding
house accommodating fewer than six people and a hut;
three storeys or less. Buildings in this category account for
■
approximately 60% of the floor area of buildings constructed
unit apartments; and
over this time period and it is estimated that they represent
95% of all building consent applications. See Figure 9.
multi unit dwellings including attached dwellings and multi
■
group dwellings including buildings where groups of
It was determined that these more 'simplistic' type buildings
people live as one large extending family (eg. Commune
(most of which are residential) are more likely to use a simple
or marae).
compliance route if available.
New Zealand is categorised into three separate climate zones.
Both NZS 4218 - 1996 Housing and Small Buildings and
For housing and small buildings climate zones 1 and 2 are
NZS 4243 - 1996 Large Buildings were been developed
grouped. Therefore there are effectively only two climate
in this light. Both standards provide a schedule of R-values
for building envelope components (Schedule Method), a
simple calculation method (Calculation Method) and a more
zones. The requirements of this code are specified for each
climate zone regardless of system.
sophisticated thermal simulation method (Modelling Method)
This standard provides three methods for demonstrating
to show compliance.
compliance. These are:
The Schedule Method specifies R-values dependent upon
■
the Schedule Method;
external building elements, etc.
■
the Calculation Method; and
The Calculation Method utilises the Overall Thermal
■
the Modelling Method.
climatic zone, glazing area, area of envelope, heating of
Transmittance value (OTTV) comparison procedure to calculate
the area-weighted envelope heat loss for both a reference
5.3.3.1 Schedule Method
building and the proposed building. The proposed building
This method requires the building envelope to have insulation
must be no worse off than the reference building in terms of
of minimum thermal R-values between conditioned and
energy performance.
unconditioned spaces. Unconditioned spaces include the
The Modelling method is essentially an alternative solution
attached garages, conservatories etc as well as outside the
to the prescriptive R-values. Although included in both
building. The R-values nominated for the roof, walls and floors
standards, it is more likely to be used for the more complex
and have different values dependant upon climate zone. In
large buildings.
all cases, these R-values are for the total construction of the
Both standards also refer to NZS 4305 - 1996 Domestic
element and not just for added insulation (as is the case in
Hot Water for additional requirements for energy efficiency.
AS 2627). See table in Figure 10.
Figure 9 - Average annual number and floor area of new buildings 1970-1993
19
Small (< 300 m2)
Residential
Non-Residential
Large (> 300 m2)
Residential
Non-Residential
Low (< 3 storeys)
Number
Total Floor Area
Average Floor Area
13,200
1,982,000 m2
150 m2
550
90,000m2
160 m2
1,000
2452,000 m2
2450 m2
700
766,000 m2
1,100 m2
Tall (> 3 storeys)
Number
Total Floor Area
Average Floor Area
8
1,600 m2
200 m2
0
12
14,000 m2
1,200 m2
38
225, 000 m2
6,000 m2
(From ‘Perforamnce-based building energy efficiency code’ by Nigel Isaacs
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In addition, the standard does not nominate the construction
of certain roof, wall or floor components that would comply
with these different R-values. NZS 4214 specifies methods of
calculating R-values for systems of different components. In
addition, industry can test materials or forms of construction
for compliance.
5.3.3.2 Calculation Method
There are also different values for "solid" and "non-solid"
construction. Solid construction is masonry, concrete etc,
whilst non-solid construction is timber framed buildings, etc.
This differentiation was originally included to the 1977 standard
to provide development time for certain construction types to
improve their thermal performance, but has been changed
for the 1996 standard.
This method allows the heat loss for the proposed building
to be compared with the heat loss of a reference building
that complies with the Schedule Method. The heat loss
is calculated over the area of each component for both
buildings. The proposed building must be equal to, or
better than the reference building.
There are also different values for components that have
heating embedded in them such as heated slabs. There are
no requirements for internal floors between two conditioned
spaces.
This method cannot be used for buildings that have glazing
areas greater than 30%. of the external wall surface area.
Figure 10
Extract from NZS 4218 - Energy efficiency
housing and small building envelope
Table 1 - Minimum R-values for schedule method
Minimum R-values
m2.0C/W
Building thermal
envelope component
Climate zones
Climate zones
1&2
3
Roof
R 1.9
R 2.5
Wall
R 1.5
R1.9
Floor
R 1.3
R 1.3
This method allows the building to have more than one type of
wall construction and a mix of glazing types. It allows the Rvalues for some components to be relaxed provided the Rvalues for other components are increased to achieve the
same result.
There are various concessions and restrictions. For example,
glazing can be greater than 30% but, if so, must be considered
as double glazed in the reference building, whilst an R-value
for any component cannot be reduced more than 40% of the
Schedule Method value.
5.3.3.3 Modelling Method
This method allows the total calculated energy use of the
proposed building to be compared to the calculated total
energy use of a reference building. This method involves using
an approved computer program. The standard does not
specify the computer program to use, so each potential
computer program must be evaluated and accepted by the
Approval Authority. It does, however, require that the computer
program be evaluated using the International Energy Agency’s
"Building Energy Simulation Test (BESTEST) and Diagnostic
Method". Other approved methods may also be used.
The same computer program is used to evaluate both the
proposed building and the referenced building. Default values
are given for certain parameters of both the proposed building
and the referenced building, such as:
■
power densities for internal gains;
■
occupancy and plug-in loads;
■
performance of plant and equipment;
■
ventilation rates; and
■
climate zones.
Note—
(1) The R-values given in this table are those applicable to the reference
building as described in this Standard .
(2) Glazing above 30% of wall area may very likely lead to solar overheating
and/or excessive heat loss. Use of the calculation method or modelling
method is advised for over 30% glazing.
(3) Carpets or floor coverings are not included in the floor R-value.
The floor R-value is met by concrete slab-on-ground and suspended floors
with continuous enclosed perimeter with 100mm drooped foil. Exposed
floors will require additional treatment e.g. pole houses.
20
Again, default values are given for various types of
occupancies (office, residential, retail, etc.)
Features that may differ in the modelling between the
proposed building and the referenced building are:
■
wall R-value and thermal mass characteristics;
■
floor R-value;
■
roof R-value and thermal mass characteristics;
■
window size and orientation, R-value, shading coefficient
and type of external shading devices; and
■
the sizes of heating, cooling and ventilation plant.
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5.3.4 NZS 4243 - 1996 Large buildings
Once again, the standard does not nominate the construction
This standard only applies to large buildings that have
details of different roof, wall or floor components that would
conditioned spaces, or artificial lighting, or both. The standard
be deemed to comply with these R-values. This is left up to
defines large buildings as any building that has a floor area
industry to provide compliant materials or forms of
exceeding 300m2. It excluding housing, industrial and ancillary
construction.
buildings and non-habitable outbuildings.
Lighting
Like NZS 4218, this standard provides the same three
methods for demonstrating compliance, however there are
significant differences for large buildings. The main difference
between NZS 4218 and NZS 4234 is the requirements for the
building thermal envelope and for lighting.
Basically, the lighting power density (W/m2) determined for
the proposed building cannot exceed the values contained
in a table in the standard for each of the relevant building
activities. These activities are broad categories and include
offices, schools, retail, storage hotels, car park and the like.
The three methods included in NZS 4243 are again:
Specific activities not covered by the table must be dealt
with using the Calculation Method.
■
the Schedule Method;
■
the Calculation Method; and
■
the Modelling Method.
There are no allowances for sophisticated lighting controls
or switching systems in any of the three methods in this
Standard. This is because it was felt that if such systems were
economic then the building owner or designer would have to
5.3.4.1 Schedule Method
incorporated them and so there would be no need to regulate.
Building thermal envelope
5.3.4.2 Calculation Method
This method is fundamentally the same as that applied to
housing and small buildings but uses different R-values as
Building thermal envelope
shown in Figure 11, which is an extract of Table 2 in the
This method provides increased flexibility in selecting the
standard. There are also different values for components
wall construction and glazing type. The thermal performance
that have heating embedded in them such as heated slabs.
of the proposed building is defined by the total wall thermal
This method cannot be used for buildings that have a
resistance and the solar aperture and this method provides
thermal resistances for components of the building envelope
Window to Wall Ratio (WWR) more than 50%.
for a range of WWRs.
The thermal resistance is determined by calculating the
Figure 11
heat loss for the proposed building and ensuring that it is
Extract from NZS 4243 Energy efficiency large buildings
Table 1 - Minimum R-values for schedule method (WWR < 50 %)
envelope component
Climate zones
1
2&3
Roof (average including glazing)
R 1.9
R 1.9
Wall R 0.3
R1.2
Floor No requirement
R 1.3
No requirement
WWR of the proposed building.
The solar aperture is defined as the fraction of total solar
radiation on the vertical wall (both opaque and glazed) that
actually enters the perimeter space. The solar aperture is
calculated for both the proposed and referenced buildings.
No requirement
The referenced building has a maximum WWR of 50% with
a glazing area R-value of 0.18, a shading coefficient of 1.0
Note—
and opaque construction R-values of those in the Schedule
(1) The R-values given in this table are those applicable to the reference
Method.
building as described in this Standard.
(2) Carpets or floor coverings are not included in the floor R-value. The floor R-value
is met by concrete slab on-ground and suspended floors with continuous
enclosed perimeter with 100 mm drooped foil. Exposed floors will require
additional treatment, e.g. office building with open car parking under.
21
heat loss for per unit area for both buildings is calculated for
WWR for the reference building may be different to the
m2.0C/W
Climate zones
Glazing
complies with the provisions of the Schedule Method. The
each component of both buildings. Using this method, the
Minimum R-values
Building thermal
no greater than the heat loss for a reference building that
(3) Climate zone boundaries are shown in Appendix B.
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Lighting
The differences between this Modelling Method and the
The building activity lighting power density limit is calculated
Modelling Method in NZS 4218 (Housing and small buildings)
using a formula in the standard. Factors include minimum
are-
efficacies for electrical circuits, luminaire utilisation factors and
■
glazing - NZS 4218 requires that the glazing area for the
design service illluminance and light loss factors. The actual
proposed and the reference building be the same. NZS
calculated lighting power density cannot exceed this limit.
4243 is the same except that if the proposed building has
a glazing area of more than 50% the reference building
5.3.4.3 Modelling Method
cannot exceed 50% of wall area. In addition the reference
building in NZS 4243 assumes single glazing with a default
Building thermal envelope and lighting
shading coefficient of 1.0 whilst there is no limitation in
As for houses and small buildings, this method calculates
NZS 4218; and
the total energy consumption for the proposed building and
compares it with the calculated total energy consumption of
■
a reference building using an approved computer program.
lighting - which is not covered in NZS 4218 is covered
in NZS 4243.
The standard does not specify any particular computer
software to use so each must be evaluated and accepted
5.3.5 NZS 4305 - 1996 Domestic hot water
by the Approval Authority. It does, however, require that the
This Standard provides details and guidance to assist
software be evaluated using a diagnostic program called
designers to meet the energy efficiency requirements for
BESTEST. Other methods approved by a suitable authority
domestic type hot water systems. These systems will mainly
may also be used.
be located in residential occupancies but may also be included
Both the proposed building and the referenced building are
evaluated using the same computer software. All factors must
This standard covers domestic type hot water systems that
be the same and default values are given for the various
have a storage capacity of no greater than 700 litres or are
parameters of both the referenced and proposed building
of the instantaneous type.
such as:
■
power densities for internal gains;
■
occupancy and plug loads;
■
performance of plant and equipment;
■
ventilation rates; and
■
climate zones.
Again, default values are given for various types of
It does not include:
■
electric storage water heaters installed in non-domestic
situations and with an energy input rating greater than
10 kW;
■
gas storage water heaters installed in non-domestic
situations and with an energy input rating greater than
45 MJ/h; and
■
hot water systems in industrial or commercial occupancies
occupancies (office, residential, retail, etc.)
that provide process hot water such as for commercial
Features that may differ between the proposed building and
washing machines in commercial laundries.
the referenced building are:
■
wall R-values and thermal mass characteristics;
■
floor R-values;
■
roof R-values and thermal mass characteristics;
■
window size and orientation, R-values, shading coefficient
and external shading devices; and
■
22
in commercial or industrial occupancies.
the sizes of heating, cooling and ventilation plant.
The requirements vary depending upon the power source
of the water heater.
I N T E R N AT I O N A L
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5.3.5.1 Electric storage water heaters
5.4
The maximum 24-hour standing heat loss (kWh/day) for
Use Of Accredited Products Or Methods
New Zealand has an accreditation system for products
the appliance is specified.
and systems. If an element is required to achieve a certain
efficiency, performance or operation, the product or system
5.3.5.2 Gas water heaters
may be accredited to achieve this requirement.
The minimum thermal efficiency is specified for storage and
instantaneous heaters operating at nominal gas consumption
Accreditation certificates are issued by the Building Industry
rates. In addition, there are requirements for the maximum gas
Authority after an appraisal finds that it complies with a certain
consumption required to maintain the average temperature of
provision of the NZBC.
the water in a storage water heater at 45 C above ambient
o
temperature.
5.3.5.3 Installation
There are also installation provisions, which include
requirements for:
■
maximum pipe lengths;
■
relief valves;
■
expansion values or chambers; and
■
vent pipes and distribution pipes including insulation
requirements and acceptable materials.
23
SECTION SIX
U N I T E D S TAT E S O F A M E R I C A
I N T E R N AT I O N A L
SECTION 6
6.1
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
U N I T E D S TAT E S O F A M E R I C A
Regulatory Framework
The building regulatory environment of the USA is, in many
ways, similar to the situation in Australia. However, Australia
has an advantage in that there is only one code writing body
and there is generally a nationally uniform code. The USA has
a number of codes that may be varied considerably around
the country. The USA is currently working towards a uniform
approach.
In addition, the ICC has taken over from the Council of
American Building Officials (CABO) which originally provided
a forum for the three code writers to meet and facilitate the
development of common requirements in codes. CABO was
the first national body formed to coordinate national uniformity
amongst the three bodies. One success was the development
of the Model Energy Code (MEC) for residential buildings
which has been adopted widely throughout the USA. The
ICC now has responsibility for the MEC.
In the USA, building control remains under the responsibility
of the individual States and, in many cases, under the control
of the smaller Counties within a State. In many cases, each
County can adopt any form of regulation they wish to but
they do not write the codes.
There are three code-writing bodies within the USA. These
code-writing bodies include the Building Officials and Code
Administrators (BOCA), the Conference of Building Officials
(ICBO) and the Southern Building Code Congress International
(SBCCI). Historically, each of these organisations developed
and maintained buildings codes which were available for
adoption by the individual States or Counties with or without
individual State or county variations.
6.2
Energy Codes In Use
In Appendix C of this report is a break down of which codes
are currently adopted in each State. There are different energy
codes adopted for residential construction and for commercial
construction. A summary of this break down is shown in
Figure 12.
Figure 12
Summary of energy codes adopted
by the States of the USA
In 1994, the International Code Council (ICC) was established
as a non-profit organisation dedicated to developing a single
set of comprehensive and coordinated national building
requirements. This is a similar mandate to that of the ABCB
in Australia.
Residential
MEC or equivalent
32
ASHRAE/IES 90.1
The ICC founders were the three principal code writers;
BOCA, ICBO and SBCCI. The ICC was founded in response
to the technical disparities between the three sets of model
codes in use throughout the USA. A problem with the three
codes was that it was difficult for building industry
professionals to move between different regions within the
USA. The main purpose of the ICC is to develop a single,
complete set of national construction codes.
Exceeds MEC
5
Exceeds ASHRAE/IES
Less than MEC
3
Less than ASHRAE/IES
1
ASHRAE/IES or equivalent
7
MEC
2
None
4
None
2
Code
Commercial
Number
Code
of States
Number
of States
43*
3
* 35 States adopt ASHRAE/IES 90.1 and 8 States adopt previous versions.
63% of States have adopted the MEC Code (or an equivalent
Since its inauguration, the ICC has developed many codes for
national adoption. One such code is the International Building
Code. The ICC’s goal is to complete a series of codes starting
with the publication of the International Building Code in the
year 2000.
25
Within the International Building Code, the International Energy
Conservation Code (IECC) is referenced. The IECC sets out
requirements for all types of occupied buildings by regulating
their exterior envelopes, heating, ventilating and airconditioning (HVAC) systems, service water heating (SWH)
systems and electrical distribution and illumination systems.
code similar to MEC) for residential buildings whilst 84% have
adopted the ASHRAE/IES 90.1 (including various editions) for
commercial buildings.
States that do adopt these codes may have varied the
requirements for their unique regional, climatic or topographical
conditions. They may also have varied the application of the
code for specific building types or ownership, particularly
when the building may be State or government owned.
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Codes to be reviewed
The HUD currently has a final rule pending to upgrade its
Although there are a quite a few different energy codes
Minimum Property Standards to the 1995 MEC level. Under
adopted throughout the 50 States of the USA, the main codes
the EPAct, all federally financed commercial and high-rise
are the MEC for residential construction and the ASHRAE 90.1
residential buildings must comply with ASHRAE/IES Standard
for commercial construction. These codes will be reviewed as
90.1-1989 and all single family homes and multi-family
part of this report.
buildings that are three stories or less must comply with
the MEC.
Looking to the future, it is also proposed to review the IECC
developed by the ICC for national adoption throughout the
USA. The current International Building Code references the
The following codes will be reviewed as part of this report:
■
the MEC 1995;
■
the ASHRAE/IES 90.1 - 1989; and
soon.
■
IECC 1998 Draft.
The 1998 IECC is the 1998 MEC that underwent a name
The Californian and Hawaiian energy code will also be
change when responsibility for code development and
reviewed is separate sections of this report.
1998 IECC and this report will concentrate on that version.
However, there is a new draft (IECC 2000) to be published
maintenance shifted from CABO to the ICC. It applies to
all new residential and commercial construction while the
6.3
Model Energy Code
bulk of the code applies to single-family homes and multifamily residences that are three stories or less.
6.3.1 Scope
In addition, Chapter 7 of the IECC provides an easy to follow
The MEC has been revised over its life and so there are a
commercial energy code that applies to simple commercial
number of editions, including 1992, 1993 and 1995. As shown
buildings. For more complex commercial buildings,
in Appendix C, different States of the USA adopt the different
ASHRAE/IES Standard 90.1-1989 is referenced. ASHRAE/IES
editions. For the purposes of this study, the latest edition
Standard 90.1-1989 can also be used for simple commercial
dated 1995 will be reviewed.
buildings and multi-family buildings that are four stories or
The MEC contains energy related building requirements that
higher.
apply to residential occupancies. Residential occupancies are
The National Energy Policy Act (EPAct), signed into law by
defined as detached one and two family buildings (houses)
President Bush in 1992, referenced the 1992 CABO MEC as
and multi-family buildings (apartments, townhouses, etc)
the energy efficiency standard to be used for new residential
that are three stories or less.
construction. EPAct required States to determine if it was
The MEC has a commercial component embedded into the
appropriate to revise their residential energy codes to meet
code. In an effort to cover all occupancies, the 1992 MEC
or exceed the 1992 MEC. Additionally, the EPAct required
included a codified version of ASHRAE/IES 90A- 1980 as its
Federal mortgage lenders to ensure that homes using their
commercial code. The 1993 and 1995 MEC editions directly
products comply with at least the 1992 MEC.
reference ASHRAE/IES 90.1. If 1993 or 1995 MEC is adopted
Subsequently, the US Department of Energy (DOE) determined
that the 1993 MEC and then the 1995 MEC provided greater
energy efficiency for residential buildings so and required
States to consider adopting the later version. The 1995 MEC
body specifically adopts a residential code without the
commercial element. Several States have adopted
ASHRAE/IES 90.1 without a residential code.
is presently the baseline for the EPAct until the DOE makes
The 1993, 1995 and 1998 IECC all reference ASHRAE/IES
a determination that the 1998 IECC is the most appropriate
90.1-1989 as a commercial code in addition to the residential
standard. That determination is expected this year.
provisions. This makes it more convenient for a state to adopt
The EPAct also requires that the States adopt ASHRAE/IES
Standard 90.1-1989, or equivalent, as the state-wide energy
one code that covers all occupancies. Some states, such as
Wisconsin, apply 90.1 to all multi-family buildings.
code for commercial and multi-family residential buildings that
A review of the MEC in this section concentrates on the
are four stories and higher. As of July 1999, 30 States have
residential component only. Refer to the IECC for a review
complied. Note that the 1998 IECC, 1993 MEC and 1995
of ASHRAE/IEC 90.1.
MEC all reference ASHRAE/IES 90.1 for commercial buildings.
26
ASHRAE/IES 90.1 is adopted by default unless the adopting
The major focus of the MEC provisions is on the insulation and
In concurrence with the EPAct, the Department of Housing
window requirements of the building envelope. However, there
and Urban Development (HUD) requires compliance with the
are requirements for heating and cooling systems, water
1992 MEC as part of its Minimum Property Standards (MPS).
heating systems and vapour and air barriers.
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6.3.2 Exemptions
6.3.4 Mandatory requirements
The following buildings are exempt from the requirements of
The MEC specifies basic requirements that are mandatory for
the MEC:
all buildings. Some of these requirements apply to the heating
and cooling systems (including ducts), hot water systems, and
■
existing buildings;
■
buildings having a very low energy consumption (<3.4
equipment identification and to sealing of the building
Btu/h.ft2 or 1 W/ft2);
envelope. The mandatory requirements applied to the:
buildings, or parts of the buildings, that are neither heated
■
building envelope;
■
identification marking;
■
heating and cooling;
■
service water heating; and
■
electric systems.
■
electrical systems. Other requirements apply to material and
nor cooled; and
■
buildings designated as historical.
6.3.3 Compliance paths
As shown in Figure 13, the MEC has mandatory requirements
in addition to the three options for compliance. The mandatory
requirements must be complied with regardless of the
compliance option chosen.
6.3.4.1 Building envelope
The building envelope must be sealed to minimise air leakage
and vapour intrusion.
All joints and penetrations in the envelope that are potential
sources for air leakage must be caulked, gasketed, weather-
Figure 13 - USA Model Energy Code
stripped, or otherwise sealed in an approved manner. These
include:
■
exterior joints around window and door frames;
■
joints between wall sole plates, floors, and exterior wall
Mandatory Requirements
Building envelope
Identification marking
Heating and cooling
Service water heating
Electric systems
panels;
■
openings for plumbing piping, electricity cabling, refrigerant
piping and gas piping in exterior walls, floors and roofs;
■
openings in the attic floor (such as where ceiling panels
meet interior and exterior walls and masonry fireplaces
and flues);
■
service hatches and access doors; and
■
recessed lighting fixtures.
Vapour retarders must be installed in all non-vented framed
ceilings, walls, and floors. Non-vented areas are framed
cavities without vents or other openings allowing the free
Prescriptive
Package
Approach
Trade-off
Approach
Software
Compliance
Approach
movement of air. The vapour retarder must have a permeability
rating of 1.0 or less and must be installed on the "warm-inwinter side" of the insulation (between the insulation and the
conditioned space).
6.3.4.2 Identification marking
Materials and equipment must be identified so that
compliance with the MEC can be determined. This includes
insulation R-values, glazing U-values, door U-values and
equipment efficiency ratings.
27
I N T E R N AT I O N A L
S U R V E Y
6.3.4.3 Heating and cooling
Heating and cooling equipment must meet specific energy
efficiency requirements. Although these requirements are
specified in the MEC, Federal regulations also support this
by requiring manufactured equipment to meet these
requirements.
Supply and return ductwork for heating and cooling systems
that is located in unconditioned spaces must be insulated to
the minimum R-value. Ducts must also be sealed to prevent
leakage.
The HVAC system must have devices for balancing air and
water systems. For air systems, this requirement can be met
by installing manual dampers at each branch of the ductwork
or by installing adjustable registers that can control the airflow
into a room. For water systems, balancing valves must be
installed to control the water flow to rooms or zones.
O F
B U I L D I N G
E N E R G Y
C O D E S
hot water system is not in operation. Piping in circulating
hot water systems must also be insulated.
There are a number of requirements for heated swimming
pools. These include:
■
equipped with an on/off pool heater switch;
■
a pool cover unless over 20% of the heating energy is
from non-depletable sources (such as solar heat); and
■
being equipped with a time clock.
6.3.4.5 Electric systems
Each multi-family dwelling unit must be equipped with a
separate electric power meter.
6.3.5 Prescriptive package approach
The HVAC system must have devices for balancing air and
water systems. For air systems, this requirement can be met
by installing manual dampers at each branch of the ductwork
or by installing adjustable registers that can control the airflow
into a room. For water systems, balancing valves must be
installed to control the water flow to rooms or zones.
The Prescriptive Package Approach involves only minimal
calculations and is the simplest method for demonstrating
compliance with the MEC insulation and window requirements
for residential buildings. These requirements are also similar to
those of the 1998 and 2000 IECC.
A range of controls and thermostats are required depending
on whether a building is a single or multi family residence.
Also specified is the number, and separation, of HVAC zones,
the controls needed for common areas in multi-family buildings
and the controls needed for shutdown.
which you can select one option. They range from 1 to 18.
Each climate zone has a table of prescriptive packages from
These packages vary in their requirements depending on
glazing area, glazing U-value, R-values of the building
envelope components and heating and cooling equipment
efficiency. If your building meets the requirements specified for
6.3.4.4 Service water heating
the package you select, then the building complies with the
SWH systems that circulate hot water by pumping must have
controls that allow the pumps to be easily turned off when the
MEC insulation and window requirements. Refer to Figure 14
Figure 14
for an example of a Table.
Example of a prescriptive package table
1995 Multi-Family Prescriptive Packages—Zone 4
Package
28
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
MAXIMUM
Glazing
Glazing
Area %
U-Value
15%
20%
20%
25%
25%
25%
30%
30%
20%
25%
30%
20%
20%
30%
30%
30%
25%
30%
any
0.90
0.75
0.75
0.70
0.65
0.65
0.60
any
0.90
0.75
any
0.90
0.75
0.70
0.65
any
0.90
Ceiling
R-Value
Wall
R-Value
Floor
R-Value
MINIMUM
Basement
Wall R-Value
Slab Perimeter
R-Value
Crawl Space
R-Value
Heating/Cooking
Equipment
Efficiency
R-13
R-19
R-13
R-19
R-19
R-13
R-26
R-19
R-13
R-19
R-19
R-30
R-13
R-26
R-19
R-13
R-19
R-19
R-11
R-13
R-11
R-11
R-11
R-11
R-11
R-11
R-11
R-11
R-11
R-11
R-11
R-11
R-11
R-11
R-11
R-11
R-13
R-11
R-11
R-13
R-11
R-11
R-11
R-11
R-11
R-11
R-11
R-11
R-11
R-13
R-11
R-11
R-11
R-11
R-5
R-5
R-4
R-6
R-4
R-4
R-5
R-4
R-5
R-4
R-4
R-5
R-4
R-5
R-5
R-5
R-5
R-4
R-2
R-0
R-0
R-2
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-2
R-0
R-0
R-0
R-0
R-6
R-5
R-3
R-6
R-4
R-5
R-5
R-4
R-5
R-4
R-4
R-5
R-4
R-6
R-5
R-5
R-6
R-5
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
High Heating
High Heating
High Heating
High Cooling
High Cooling
High Cooling
High Cooling
High Cooling
High Heat/Cool
High Heat/Cool
I N T E R N AT I O N A L
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
The insulation R-values listed for each package are the
6.3.7 Software compliance approach
minimum allowed for that package. R-value requirements refer
The Software Compliance Approach is similar to the Trade-off
to the R-value of the insulation only. Wall and ceiling insulation
Approach with the exception that high efficiency equipment
R-values refer to the sum of the stud cavity insulation plus any
can be traded-off. The approach uses a software package
insulating sheathing.
called MECcheck.
Glazing is expressed as a percentage of the ratio of the
The Prescriptive Package Approach specifies thermal
glazing area to the wall area. Glazing also includes translucent
envelope requirements in terms of R-values. These correspond
glass doors, skylights, and basement windows. The glazing
to maximum U-values for walls, ceilings, floors, crawl space
area and window U-value requirements for any package can
walls and basement walls. There are also minimum R-values
be varied by using the Trade-Off Approach (detailed in 6.3.6).
for slab floors. To comply with the MEC, a building must be
constructed with components meeting or exceeding these
Some of the packages specify high-efficiency heating or
requirements.
cooling equipment, or a combination of both. High-efficiency
heating units are those that have an Annual Fuel Utilisation
Efficiency (AFUE) of at least 90% or a Heating Seasonal
Performance Factor (HSPF) of at least 7.8. High-efficiency
cooling units have a Seasonal Energy Efficiency Ratio (SEER)
of at least 12.
6.3.6 Trade-off approach
This is the classic method of comparing a standard building
with a proposed building. This approach allows you to trade-
However, the U-value of a given assembly may be increased
or the R-value may be decreased, provided the total heat
gain or loss for the entire building does not exceed the total
needed to meet the prescriptive requirements. The software
package MECcheck performs a simple U-value x Area
calculation for each building assembly to determine the overall
UA of the building. MECcheck is only one software package
that performs this analysis and other appropriate packages
can be used eg. REM Design and MICROPAS.
off all building envelope components including ceilings, walls,
The UA for the proposed building is compared to that of a
floors, windows and doors. The trade-off approach determines
building conforming to the MEC prescriptive requirements.
whether your building as a whole meets the MEC insulation
If the total heat loss (represented as a UA) through the
and window requirements. Note that heating and/or cooling
systems are not traded-off in this approach
envelope of the building does not exceed the total heat
loss from the same building conforming to the prescriptive
requirements, then the building complies. A trade-off for
Any individual component, or all of the components, of
the prescriptive Table may be traded off. For a particular
component, such as a ceiling, an R-value is specified. For the
proposed building, this R-value has a corresponding U-value,
which is a measure of how well a component conducts heat.
In addition, under this method, a performance approach
can be utilised comparing the annual energy consumption
of the proposed building to a building complying with the
UA method. Software packages are used and follows the
The U-value is multiplied by the area of the component to
approach outlined in IECC 1998 for residential buildings.
give the UA.
Refer to section 6.4.2.1 for an outline of this method.
The UA of an assembly is the U-value of that assembly times
The software packages available under this method will
the surface area through which heat flows. The UA for the
typically give you an annual energy consumption for the
entire building is the sum of all UAs for each assembly in the
proposed and budget building or an energy use per unit
building envelope, giving a total UA for the building envelope.
of floor area. Some of the programs determine the budget
A larger UA indicates more heat loss, because of a larger
building automatically and others require that the user
surface area, or higher U-values, or both.
provide the input for the budget building. Currently there
The UA is then determine for the standard building. In this
case the standard U-value is stated for each climate zone.
This U-value is multiplied by the same floor area to determine
the standard building UA. If the UA for the proposed building
is less than the UA for the standard building, the solution is
acceptable. In the case of the whole building being traded-off,
the sum of the UAs for the proposed building must be less
29
high-efficiency equipment can also be performed.
than the sum of the UAs for the standard building.
is no national certification for the software.
I N T E R N AT I O N A L
6.4
S U R V E Y
International Energy
Conservation Code (IECC)
O F
B U I L D I N G
■
E N E R G Y
C O D E S
"Energy Efficient Design of New Buildings except Low-Rise
Residential Buildings"
■
6.4.1 Introduction
"Fundamentals Handbook", the codified version of the
ASHRAE/IES Standard 90.1-1989.
The USA International Building Code references the IECC
which, in turn, sets out requirements for all types of occupied
The IECC divides American into 38 climatic zones for
buildings. It covers their exterior envelopes, HVAC systems,
commercial buildings and into Heating Degree-Day zones for
SWH systems and electrical distribution and illumination
residential buildings. Provisions vary for these climatic zones.
systems.
The IECC is divided into the requirements for residential
This review will only deal with the 1998 draft but a new draft
buildings and the requirements for commercial buildings
is due for release later this year. Where possible, comment
and these are described below.
will be made on any future provisions or significant changes
proposed in the 2000 draft code. Two such changes will be
6.4.2 Residential buildings
the inclusion of a simple prescriptive method for residential
For residential buildings to comply with the IECC, their
compliance and an expanded section for commercial
design needs to follow one of the two methodologies and
mechanical systems. The latter will handle complex
five procedures illustrated in Figure 15.
mechanical systems in addition to the unitary single zone
systems currently covered in the 1998 IECC.
6.4.2.1 Annual energy consumption
The first method of compliance is by calculating the annual
The IECC exempts certain buildings from needing to
energy consumption of the building. This is an approach for
complying. These include:
■
allows flexibility in the design of the building and individual
the building that has a peak design rate of energy usage
components.
less than 10.7
■
the entire building and its energy-using sub-systems and
a part of a building separated from the remainder of
W/m2;
and
Compliance is achieved if the annual energy consumption
buildings which are neither heated nor cooled. This mainly
for the proposed building is less than the annual energy
includes buildings used for industrial or manufacturing
consumption for a similar building known as the "standard
purposes. The 2000 IECC only exempts the building
building".
envelope, not the lighting or SWH system within a building
that is neither heated or cooled.
The IECC contains prescriptive methods of compliance as well
as referencing many of the ASHRAE/IES Standards including:
Figure 15
The standard building and the proposed building must have
the same energy sources, geometry, floor area, exterior design
conditions, occupancy, thermal data, etc. Chapter 4 of the
code sets out the basic parameters of the design for both the
USA residential building conpliance routes
Compliance
Annual Energy
Consumption Method
Annual energy
analysis
30
Building
Envelope Method
Performance on an individual
componants basis
Compliance by total building
envelope performance
Compliance by acceptable
practice of an individual
componant basis
Compliance by prescriptive
specification on an
individual componant basis
I N T E R N AT I O N A L
S U R V E Y
proposed and standard buildings. For example, the proposed
building can utilise the benefits of a renewable energy source
such as solar energy or the benefits of shading to windows.
The standard building is designed with its envelope, building
elements and energy-consuming systems conforming to
Chapter 5 of the code which specifies the prescriptive
requirements for building elements.
The standard building assumes a certain consumption
of energy for power services (hot water, heating, etc.).
However, it does not allow for shading of windows.
The actual calculations for determining the annual energy
usage can be found in the ASHRAE Fundamentals Handbook.
6.4.2.2 Building Envelope Method
The second method of achieving compliance, the Building
Envelope Method, is located in Chapter 5 of the IECC.
It places requirements on the building envelope to restrict
energy loss by thermal transmittance through the envelope.
There are four procedures for demonstrating compliance.
Thermal transmittance U values are calculated for walls, roofs
and floors and R-values are calculated for heated or heated
slabs, basement walls and crawl spaces. These values
dependent on the heat capacity of the walls, heating degreedays of the zone and R-values of the components. These are
the set values that must be met by at least one of the
following four procedures.
O F
B U I L D I N G
E N E R G Y
C O D E S
Compliance by acceptable practice on an individual
component basis
Similar to Compliance by performance on an individual
components basis, each individual component’s U or R-value
is calculated and cannot exceed the maximum set values.
However in this case, the actual components can be taken
from an Appendix that outlines the typical constructions
including some form of insulation and the corresponding U or
R-values. This saves the designer calculating the R or U value
and then working out what type of wall, roof or floor to use,
including how much insulation is needed. The designer can
refer to a table that specifies a standard construction with a
set thermal performance rating.
Compliance by prescriptive specification on
an individual component basis
Under the previous three procedures, openings in the building
envelope were accounted for in the calculations of the overall
component U-value or R-value. This took into account their
thermal transmittance and their areas, individually or
collectively. Under this procedure the R-value insulation is
specified for ceilings, walls and floors dependant upon the
area and U value of the glazing. Tables are provided for 8, 12,
15, 18, 20 and 25 percentage glazing of the gross external
wall area. Figure 16 is an extract of the code and the relevant
table applicable to 12% glazing area.
Other requirements
Compliance by performance on an individual
components basis
Formulas are given to enable the thermal transmittance
value for each component of the building to be calculated.
These calculated values cannot exceed the set calculated
maximum values.
Compliance by total building envelope performance
An individual component of the envelope of the proposed
building can exceed its maximum U-value or R-value.
However, the total thermal transmission for the proposed
building envelope must not exceeding that for a building
complying with all the maximum U-values or R-values.
31
This procedure allows for design flexibility. For example, the
allowable thermal transmission heat gain or loss through the
windows can be exceeded provided credits are gained on
other factors such as roof or wall insulation. Note that building
orientation is not considered under Chapter 5 as this code
deals heat loss from the building and not heat gain. In
addition, no credit is given for installing a more efficient water
heater, or air heating or cooling system. Minimum water
heating, air heating and cooling efficiencies are regulated by
the Federal government under the National Appliance and
Energy Conservation Act and also under
the Energy Policy Act.
Other requirements, regardless of the method or procedure
chosen in Chapter 5, include specific measures for mechanical
systems and equipment such HVAC equipment.
Some types of equipment, such as swap or evaporative
coolers, do not have minimum efficiency ratings in the IECC.
If the equipment rating does not correspond to the tabulated
values in the IECC then the alternative ASHRAE/IES standard
needs to be met instead. The efficiency ratings in ASHRAE
that are not printed in the IECC relate to commercial size
equipment.
There are further requirements for HWS systems including
the performance efficiency of water heaters, storage tanks
and boilers. Automatic temperature controls are also required
in accordance with the ASHRAE/IES HVAC Systems and
Applications Handbook. Provisions are also made for
swimming pools.
Electrical power and lighting have requirements. These include
separate metering of electrical energy consumed by each
tenant of individual dwelling units. Common areas of multifamily buildings, such as shared laundry rooms and enclosed
hallways, are required to meet the ASHRAE/IES provisions for
a lighting power budget similar to that for non-residential
buildings. However, the inside lighting of most individual
dwelling units do not have to meet lighting provisions.
I N T E R N AT I O N A L
Figure 16
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
Extract from IECC 1998 of a table for the prescriptive building envelope
TABLE 502.2.4(2) PRESCRIPTIVE BUILDING ENVELOPE REQUIREMENTS TYPE A-1 RESIDENTIAL BUILDINGS,
WINDOW AREA 12 PERCENT OF EXTERIOR WALL AREA
MINIMUM
Heating
DEGREE DAY
GLAZING
U-VALUE
Ceiling
R-Value
Wall
R-Value
Floor
R-Value
Basement wall
R-Value
Slab perimeter
R-Value and
depth
Crawl space wall
R-Value
0-449
500-999
I,000-1.499
I,500-1,999
2,000-2,499
2,500-2,999
3,000-3,499
3,500-3,999
4,000-4,499
4,500-4,999
5,000-5,499
5,500-5,999
6,000-6,499
6,500-6,999
7,000-8,499
8,500-8,999
9,000-12,999
any
any
0.75
0.75
0.65
0.60
0.60
0.60
0.55
0.50
0.45
0.45
0.40
0.40
0.40
0.40
0.40
R-13
R-19
R-19
R-19
R-l9
R-26
R-30
R-30
R-38
R-38
R-38
R-38
R-38
R-49
E-49
R-49
R-49
R-11
R-11
R-11
R-11
R-13
R-13
R-13
R-13
R-13
R-14
R-16
R-17
R-18
R-21
R-21
R-21
R-21
R-11
R-11
R-11
R-11
R-11
R-13
R-15
R-19
R-19
R-19
R-19
R-19
R-19
R-19
R-19
R-19
R-19
R-0
R-0
R-0
R-4
R-5
R-5
R-6
R-8
R-9
R-9
R-9
R-9
R-10
R-10
R-10
R-16
R-16
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-4, 2ft.
R-4, 2ft.
R-5, 2ft.
R-6, 2ft.
R-6,2h.
R-6, 4ft.
R-7, 4ft.
R-9, 4ft.
R-9, 4ft.
R-11, 4ft.
R-0
R-4
R-5
R-5
R-5
R-5
R-6
R-10
R-12
R-16
R-16
R-16
R-16
R-17
R-17
R-17
R-17
6.4.3 Commercial buildings
6.4.3.1 Introduction
In the IECC, there are two methods by which the compliance
of commercial buildings can be demonstrated. They are■
Chapter 6 which refers to the method contained in
ASHRAE/IES Energy Code for Commercial and High
Rise Residential Buildings; and
■
Chapter 7 which details the design of commercial
buildings by acceptable practice.
6.4.3.2 The method contained in ASHRAE/IES
This standard sets out the minimum basic requirements
for buildings systems including:
32
The ASHRAE standard set limitations on the equipment
and systems used and procedures for calculating the overall
thermal transmittance of the building envelope. It also sets
out mandatory requirements for air leakage, thermal resistance
of below grade components, etc.
The standard then sets out two methods of compliance.
The Systems/Component Method or the Building Energy
Cost Budget Method. See Figure 17 for an overall picture
of how to achieve compliance.
This standard is generally not intended for manufacturing,
commercial or industrial processing. These types of buildings
would need to comply with Chapter 7 only if they are heated
or cooled as per the scope of this code. Nor is it applicable
to buildings that have a gross floor area of less than 10m2.
■
building envelope;
Systems/Component Method
■
electric power;
■
lighting;
The systems/component method provides two optional
approaches. These are-
■
distribution of energy;
■
the Prescriptive Criteria approach; and
■
HVAC;
■
the Systems Performance Criteria approach.
■
SWH; and
■
energy management.
This standard is generally not intended for use with
manufacturing, commercial or industrial processes. These
types of buildings would need to comply with Chapter 7 only
if they are heated or cooled. Buildings which have a gross
floor area of less than 10m2 are also exempted.
The Prescriptive Criteria
The prescriptive criteria consist of "Alternative Component
Packages" (ACP) which are in Tabular format for each of the
38 climate conditions. Each package covers the maximum
thermal transmittance U values of the roof, external walls,
floors and below grade surfaces. See Figure 18 for a typical
ACP table.
I N T E R N AT I O N A L
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
This method offers very little flexibility with the exception of
The calculations and tolerances in the criteria on thermal
fenestration, for which it includes variables such as shading
transmittance U values for floors, roofs and walls below grade
coefficients, overhangs, etc.
are slightly different under this method but are essentially the
same as the ACP Tables.
Systems Performance Criteria
The Systems Performance Criteria is only available for the
The Systems Performance Criteria is also available for
building envelope and the lighting system within a building.
determining the interior lighting power allowance (ILPA).
See Figure 17. All other components must comply with the
It allows greater flexibility and a more accurate and detailed
Prescriptive Criteria. A computer program called ENVSTD (for
calculation procedure. To simplify the use of this approach,
ENVelope STandarD) is used in the design of the external walls
the equations and data have again been incorporated into a
and fenestration.
computer program called LTGSTD (For Lighting Standard).
Figure 17
Overall picture of achieving compliance in ASHRAE / IES Energy Code
Basic Requirements
Electric power
HVAC system and equipment
Building Envelope
SWH
Energy Management
Proposed Design
System/Componant Method
Building Energy Cost Budget
Lighting
Prescriptive
Criteria
Performance
Criteria
Building Envelope
Prescriptive
Criteria
Energy Cost Budget
Proposed Design
Design Energy
Consumption
(DECON)
Performance
Criteria
HVAC System
Prototype
Building
Design Energy
Cost (DECOS)
Prescriptive Criteria
Energy Cost Budget
(ECB)
Service Water Heating
Prescriptive Criteria
All comply
No
Yes
33
No
Compliance achieved
Yes
Reference
Building
Is DEBOS ≤ ECB
I N T E R N AT I O N A L
Figure 18
HDD50-
-
1000
San Francisco CA
≤
300
Santa Maria CA
VSEW -
>
845
HDD65 -
>
3000
1
DESIGN PARAMETERS
Projection
Factor
(FF)
Range
0.00 -0.25
0.00 -1.50
0.26 -0.50
0.51 +
0.00 - 0.25
1.51-3.00
B U I L D I N G
TABLE NUMBER:
CDD65 -
Internal
Load
Density
(ILD)
Range
O F
E N E R G Y
C O D E S
Extract from ASHRAE/IES 90.1 of an Alternative Component Package Table
ALTERNATE COMPONENT PACKAGES FOR:
0.26 -0.50
0.51 +
0.00 -0.25
3.01 - 3.50 0.26 - 0.50
0.51 +
34
S U R V E Y
Shading
Coefficient
(Scx)
Range
1.00 - 0.72
0.71 - 0.61
0.60 - 0.51
0.50 - 0.39
0.38 - 0.26
0.25 - 0.00
1.00 - 0.72
0.71 - 0.61
0.60 - 0.51
0.50 - 0.39
0.38 - 0.00
1.00 - 0.72
0.71 - 0.61
0.60 - 0.51
0.50 - 0.00
1.00 - 0.72
0.71 - 0.61
0.60 - 0.51
0.50 - 0.39
0.38 - 0.26
0.25 - 0.00
1.00 - 0.72
0.71 - 0.61
0.60 - 0.51
0.50 - 0.39
0.38 - 0.00
1.00 - 0.72
0.71 - 0.61
0.60 - 0.51
0.50 - 0.00
1.00 - 0.72
0.71 - 0.61
0.60 - 0.51
0.50 -0.39
0.38 - 0.26
0.25 - 0.00
1.00 - 0.72
0.71 - 0.61
0.60 - 0.51
0.50 - 0.39
0.38 - 0.00
1.00 - 0.72
0.71 - 0.61
0.60 - 0.51
0.50 - 0.00
8A-5
MAXIMUM PERCENT FENESTRATION
MAXIMUM WALL U-VALUE Light-Weight Walls
Fenestration U-Value (Wef)
ILD Range
0.00 -3.50
Base Case
Percent
Fenestration
HC Range
All Insulation
Positions
0-100
0.00 - 4.9
0.13
Perimeter daylighting1
0.46
VLT<SC
0.72 0.52
VLT>=SC
0.46
0.72
0.52
to
to
to
to
to
to
0.53
0.47
0.00
0.53
0.47
0.46
21
25
29
34
43
56
29
35
40
46
56
38
45
51
57
17
21
24
28
36
51
24
29
39
39
49
31
37
43
50
14
17
21
24
31
45
20
25
29
34
43
27
32
37
43
21
26
31
36
46
65
31
37
43
51
63
40
48
55
64
17
21
25
29
38
55
24
30
35
41
53
32
39
45
54
14
18
21
25
32
48
21
25
30
35
45
27
33
39
46
22
26
31
37
47
68
31
38
44
52
66
41
49
57
67
17
21
25
29
38
57
24
30
35
42
54
32
39
46
55
14
18
21
25
33
49
21
25
30
36
46
27
33
39
47
23
28
32
37
46
59
32
38
44
50
59
41
48
54
60
23
28
32
38
47
62
32
39
44
51
61
41
49
55
62
22
27
31
36
45
60
31
37
42
48
58
39
46
52
59
24
29
34
40
50
69
34
41
47
55
68
44
52
60
69
24
29
34
40
51
71
34
41
47
56
69
44
53
61
70
22
27
32
38
48
68
32
39
45
53
66
42
50
58
67
24
30
35
41
53
74
35
42
49
58
72
46
55
63
73
25
30
36
42
54
77
35
43
50
59
75
47
56
65
75
24
29
34
41
53
75
34
42
49
58
72
45
55
63
73
MAXIMUM WALL U-VALUE (Uow) Mass Walls
ILD Range
Percent
Fenestration
21
74
ILD Range
Percent
Fenestration
17
77
ILD Range
Percent
Fenestration
14
75
0.00 - 1.30
HC Range
5.0 - 9.9
10.0 - 14.9
15.0 +
5.0 - 9.9
10.0 - 14.9
15.0 +
Interior
Insulation
0.18
0.28
0.37
0.16
0.22
0.29
Exterior
Insulation
0.21
0.36
0.38
0.21
0.31
0.34
Interior
Insulation
0.21
0.37
0.49
0.17
0.26
0.36
Exterior
Insulation
0.21
0.47
0.52
0.21
0.36
0.37
Interior
Insulation
0.21
0.38
0.53
0.17
0.27
0.37
Exterior
Insulation
0.21
0.50
0.57
0.21
0.36
0.39
0.51 - 3.00
HC Range
5.0 - 9.9
10.0 - 14.9
15.0 +
5.0 - 9.9
10.0 - 14.9
15.0 +
3.01 -3.50
HC Range
5.0 - 9.9
10.0 - 14.9
15.0 +
5.0 - 9.9
10.0 - 14.9
15.0 +
OTHER ENVELOPE CRITERIA
Minimum R-Value
Wall Below Grade
Unheated Slab on Grade
Horizontal
Vertical
24"
11
6
36"
9
5
48"
8
4
Maximum R-Value
Roof
0.088
Wall Adjacent to Unconditioned Space
0.21
Floor over Unconditioned Space
0.094
I N T E R N AT I O N A L
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
Building Energy Cost Budget Method
If the building is more than four storeys or is to have more
Since proposed designs may use different energy sources,
than 40% glazing, Chapter 7 can still be used for the lighting
energy cost is used as a common denominator. The Building
and mechanical systems. Compliance paths can be mixed.
Energy Cost Budget Method, unlike the System/Component
For example, Chapter 7 can be used for the envelope and
Method, allows greater flexibility and innovative energy
lighting and ASHRAE/IES 90.1 for the mechanical systems.
conservative designs utilising day-lighting, passive solar
The 2000 IECC broadens the scope of the current Chapter 7.
heating, heat recovery, better zonal temperature control,
It will permit the prescriptive envelope method to be used for
thermal storage, off peak electrical energy, etc.
buildings with up to 50% of the gross area of the above grade
This is basically a method that compares annual energy
walls in glazing and with not have a limit on the number
costs of the proposed building to a similar prototype or
of storeys.
reference building.
In chapter 7, R-values are specified in tables for all the building
The prototype or reference building, which is similar in size
envelope components such as the roof, walls, floors, glazing,
and usage to the proposed building, must meet all the
doors. R-values are specified for each component for each
requirements of the prescriptive and performance criteria in
different climatic zone, for different percentages of glazed area
the System/Component Method. However, the proposed
to the perimeter area of the building (up to a maximum of
building may deviate from the Prescriptive and System
40%) and for different construction types and materials for
Performance Criteria of the previous clauses.
certain components. Figure 19 is an example of the table.
It is for Table 702.2(4) for Climate Zone 1a and glazing area
The first step is to determine the monthly energy consumption
of 10% or less of the above grade area.
of the proposed building (DECON) and the prototype building
(BECON) using the energy analysis procedure.
There are also further prescriptive requirements for the
building envelope, the HVAC systems, the SWH systems
The second step is to calculate the monthly energy costs
of both buildings by applying the applicable local cost rate to
the estimated consumption. The calculated monthly costs are
then totalled to determine the annual energy costs.
envelope include sealing of penetrations and moisture control.
Energy efficiency ratings are specified for the HVAC, SWH
and lighting systems but only to certain types of systems.
To comply, the annual energy cost of the proposed building
If the particulars of the proposed systems are outside the
(DECOS) must not be greater than the annual energy cost
scope of these parameters, then compliance must be by
of the prototype building (ECB).
the ASHRAE/IES route.
6.4.3.3 Design by acceptable practice
for commercial buildings
In the ASHRAE/IES Standards there are a series of basic
Chapter 7 of the IECC only deals with buildings that are less
than four storeys high and have glazing that is not greater than
40% of the gross area of the above grade walls. All buildings
outside this scope must comply with Section 6 of the IECC
which, in turn, refers to ASHRAE/IES Energy Code for
Commercial and High Rise Buildings. Refer to clause 6.4.3.2.
35
and the lighting systems. The requirements for the building
provisions that must be complied with and for which there
are no alternatives.
I N T E R N AT I O N A L
Figure 19
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
Extract from ASHRAE/IES 90.1 of a table for envelope requirements
TABLE 702.2(4) BUILDING ENVELOPE REQUIREMENTS2 —CLIMATE ZONE1a
36
GLAZING AREA 10 PERCENT OR LESS OF ABOVE-GRADE WALL AREA
ELEMENT
Skylight (U-value)
Slab or below grade wall (R-value)
Windows and glass doors
SHGC
PF < 0.25
Any
0.25 < PF < 0.50
Any
PF > 0.50
Any
Roof assemblies (R-value)
Insulation between framing
All-wood joist/truss
R-13
Metal joist/truss
R-13
Concrete slab or deck
NA
Metal purlin with thermal block
R-19
Metal purlin without thermal block
R-30
Floors over outdoor air or unconditioned space (R-value)
Insulation between framing
All-wood joist/truss
R-0
Metal joist/truss
R-0
Concrete slab or deck
NA
Above Grade-Walls (R-value)
No Framing
Framed
R-value cavity
NA
R-value continuous
NA
CMU, > 8 in, with integral insulation
R-value cavity
NA
R-value continuous
R-0
Other Masonry Walls
R-value cavity
NA
R-value continuous
R-0
GLAZING AREA 10 PERCENT BUT NOT GREATER THAN 25 PERCENT OF ABOVE-GRADE WALL AREA
ELEMENT
Skylight (U-value)
Slab or below grade wall (R-value)
Windows and glass doors
SHGC
PF < 0.25
0.6
0.25 < PF < 0.50
0.7
PF > 0.50
Any
Roof assemblies (R-value)
Insulation between framing
All-wood joist/truss
R-19
Metal joist/truss
R-19
Concrete slab or deck
NA
Metal purlin with thermal block
R-25
Metal purlin without thermal block
X
Floors over outdoor air or unconditioned space (R-value)
Insulation between framing
All-wood joist/truss
R-0
Metal joist/truss
R-0
Concrete slab or deck
NA
Above Grade-Walls (R-value)
No Framing
Framed
R-value cavity
NA
R-value continuous
NA
CMU, > 8 in, with integral insulation
R-value cavity
NA
R-value continuous
R-0
Other Masonry Walls
R-value cavity
NA
R-value continuous
R-0
GLAZING AREA OVER 25 PERCENT BUT NOT GREATER THAN 40 PERCENT OF ABOVE-GRADE WALL AREA
ELEMENT
Skylight (U-value)
Slab or below grade wall (R-value)
Windows and glass doors
SHGC
PF < 0.25
0.4
0.25 < PF < 0.50
0.5
PF > 0.50
0.6
Roof assemblies (R-value)
Insulation between framing
All-wood joist/truss
R-19
Metal joist/truss
R-25
Concrete slab or deck
NA
Metal purlin with thermal block
R-25
Metal purlin without thermal block
X
Floors over outdoor air or unconditioned space (R-value)
Insulation between framing
All-wood joist/truss
R-0
Metal joist/truss
R-0
Concrete slab or deck
NA
Above Grade-Walls (R-value)
No Framing
Framed
R-value cavity
NA
R-value continuous
NA
CMU, > 8 in, with integral insulation
R-value cavity
NA
R-value continuous
R-0
Other Masonry Walls
R-value cavity
NA
R-value continuous
R-0
CONDITION/VALUE
1
R-0
U-value
Any
Any
Any
Continuous Insulation
R-11
R-12
R-11
R-12
R-12
Continuous Insulation
R-0
R-0
R-0
Metal Framing
Wood Framing
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
CONDITION/VALUE
1
R-0
U-value
Any
Any
Any
Continuous Insulation
R-14
R-15
R-14
R-15
R-15
Continuous Insulation
R-0
R-0
R-0
Metal Framing
Wood Framing
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
CONDITION/VALUE
1
R-0
U-value
0.7
0.7
0.7
Continuous Insulation
R-16
R-17
R-16
R-17
R-17
Continuous Insulation
R-0
R-0
R-0
Metal Framing
Wood Framing
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
SECTION SEVEN
CALIFORNIA
I N T E R N AT I O N A L
SECTION 7
7.1
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
CALIFORNIA
Regulatory Framework
■
by mechanical heating or mechanical cooling.
The California Building Standards Code is administered by the
California Building Standards Commission. This code is also
■
Low-rise residential buildings that are heated or
mechanically cooled.
referred to as Title 24, which is one of the 26 titles of the
California Code of Regulations.
Any buildings that are directly or indirectly conditioned
■
Semi-conditioned non-residential occupancies.
The Californian Building Code is divided into 11 Parts, namely:
Low-rise residential buildings include detached and attached
Part 1
Administrative
dwellings, apartment buildings, lodging houses, etc that are
Part 2
General building and construction
provisions including fire and life safety
three storeys or less. Hotels and motel are not under this
classification.
Scope of the Requirements
Part 3
California Electrical Code
Part 4
California Mechanical Code
Part 5
California Plumbing Code
Part 6
California Energy Code
Part 7
California Elevator Safety Construction Code
Part 8
California Historical Building Code
Part 9
California Fire Code
7.3
Part 10
California Code for Building Conservation
There are two categories of buildings within the California
Part 12
California Reference Standards Code
Energy Code. These are:
The CEC specifies requirements for:
■
the building envelope components;
■
Space-conditioning systems;
■
SWH systems; and
■
lighting systems.
Categories of Buildings
As part of this study, Part 6 of the California Energy Code
■
low-rise residential buildings; and
(CEC) has been reviewed. There are two companion
■
non-residential, high-rise residential, and hotel/motel
documents to the California Energy Code that sets out the
buildings.
way in which compliance is achieved. They are the Residential
Manual and the Non-Residential Manual.
For a building to achieve energy efficiency compliance it must
meet the requirements of the mandatory section which mainly
7.2
Scope
deals with the certification of the design and the installation of
manufactured devices. The building must also meet the
The requirements of the CEC are applicable to the following
requirements of either the performance or prescriptive
buildings:
approach.
■
38
Occupancy groups-
There are further requirements outlined in the code that cover:
-A
Assembly;
-B
Business;
-E
Educational;
-F
Factory and industrial;
-H
Hazardous;
-M
Mercantile;
7.4
-R
Residential; and
There are 16 climate zones across the State of California
-S
Storage.
designated in the CEC.
■
semi-conditioned non-residential buildings; and
■
new construction in existing buildings for both residential
and non-residential use.
Climate Zones
I N T E R N AT I O N A L
7.5
S U R V E Y
O F
Requirements For Non-Residential, High-Rise
Residential, And Hotel/Motel Buildings
B U I L D I N G
■
the energy efficiency of luminaries in high-rise
residential occupancies;
■
maximum area controls;
■
controls to reduce lighting intensity such as dimmers
either the requirements of a performance approach or a
prescriptive approach. Refer Figure 20.
C O D E S
These requirements include:
Non-residential, high-rise residential, and hotel/motel buildings
must comply with the mandatory provisions and also with
E N E R G Y
and dual switching;
7.5.1 Mandatory provisions
Sub-chapter 3 of the CEC specifies requirements for the
design and installation of space-conditioning and SWH
systems and equipment. The requirements include:
■
automatic switching off controls; and
■
circuitry requirements.
After the mandatory provisions have been met, the building
minimum outdoor air quantities and energy efficient
methods of delivery;
envelope, space-conditioning, lighting and SWH systems
■
zoning;
or the prescriptive approach.
■
thermostatic controls for zoning;
■
heat pump controls;
The performance approach is based on calculating the energy
■
shut-off and reset controls;
budget for the proposed building and ensuring that it is no
■
pipe insulation; and
■
air ducts requirements including insulation, sealing,
connections, etc.
■
must also comply with either the performance approach
7.5.2 Performance approach
greater than the energy budget for a standardised building.
The energy budget takes into account the energy likely to be
used by the space-conditioning, lighting and SWH systems.
Note that it only takes into account energy from depletable
Sub-chapter 4 of the CEC specifies requirements for the
sources with solar power and non-depletable sources being
design and installation of lighting systems and equipment.
exempted from the calculations.
Figure 20
California Energy Code compliance routes for non-residential,
high-rise residential, and hotel/motel buildings
Compliance for non-residential, high-rise residential, and hotel/motel buildings
Mandatory Provisions for HVAC
SWH systems and equipment
Lighting systems
Prescriptive Approach
Lighting
systems
HVAC
SWH systems
Envelope component
approach
39
Performance Approach
Building
envelope
Annual Energy Budget
(Use) Method
Overall envelope
approach
I N T E R N AT I O N A L
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
This approach provides flexibility for the designer as it
allows some systems within the building to use more energy,
but compensate by having a more energy efficient building
envelope.
The energy budget is expressed in Btu per square foot
of conditioned floor area per year.
The standard building must generally comply with the
mandatory provisions of Sub-chapters 3 and 4 for the
space-conditioning, lighting and SWH systems as
7.5.3 Prescriptive approach
discussed previously.
The prescriptive approach has requirements for each of
the different building elements. These building elements
include the building envelope and the space-conditioning,
lighting and SWH systems.
A computer program is used for the calculation of the
expected energy consumption of both the proposed building
and the standard building and the program must be approved
by the Commission. Where applicable, values must be the
same for both the proposed building and the standard building
such as the level of zoning, the orientation and the gross
envelope area. Window area is flexible for the proposed
building whereas the window area in the standard building
cannot exceed certain values. For other systems such as
lighting, minimum values are applied to the standard building.
Building envelope
There are two further approaches available for the
building envelope to met the requirements. They are:
■
the Envelope Component Approach; and
■
the Overall Envelope Approach.
Envelope Component Approach
The proposed building's energy budget is calculated using
the parameters of the actual proposed building. Energy usage
is calculated for the space conditioning, lighting and SWH
systems based on the actual design parameters. The
computer program takes into account the building envelope
properties for insulation and energy efficiency and these can
be selected so as to ensure that the proposed building budget
does not exceed the standard building energy budget.
Figure 21
The Envelope Component Approach specifies either an Rvalue for the particular component or a U-value for the overall
assembly of components such as the roof, walls, floors, etc.
This is presented in tabular form for each of these building
components assemblies and each climate zone. Windows
and skylights are also included. Refer to Figure 21, which is
an extract of Table 1-H of the CEC. It contains the prescriptive
envelope criteria for non-residential buildings.
Prescriptive requirements for non-residential buildings
TABLE 1-H—PRESCRIPTIVE ENVELOPE CRITERIA FOR NONRESIDENTIAL BUILDINGS
(Except high-rise residential buildings and guest rooms of hotel/motel buildings)
40
Roof/Ceiling
R-value or
U-value
Wall
R-value or
U-value
wood frame
Metal frame
Mass/7.0<HC<15.0
Mass/15.0<HC
Other
Floor/Soffit
R-value or
U-value
Mass/7.0<HC
Other
Windows
U-value
Relative solar heat gain
North
Nonnorth
Skylights
U-value
Solar heat gain coefficient
Transparent
Translucent
1,16
2-5
19
0.057
19
0.057
13
CLIMATE ZONES
6-10
11-13
14-15
11
0.078
19
0.057
19
0.057
11
11
13
13
0.084
0.182
0.340
0.360
0.084
0.092
0.189
0.430
0.650
0.092
0.092
0.189
0.430
0.690
0.092
0.084
0.182
0.430
0.650
0.084
0.084
0.182
0.430
0.400
0.084
19
11
11
13
13
0.097
0.050
0.158
0.076
0.158
0.76
0.97
0.78
0.158
0.76
0.72
1.23
1.23
0.72
0.72
0.77
0.50
0.82
0.62
0.82
0.62
0.77
0.50
0.77
0.50
0.85
1.31
1.31
0.85
0.85
0.44
0.70
0.61
0.75
0.61
0.75
0.44
0.70
0.44
0.70
I N T E R N AT I O N A L
S U R V E Y
There are further restrictions on the ratio of window area to
O F
B U I L D I N G
■
the gross exterior wall area. A windows solar heat gain must
also not exceed a value determined by calculation.
Overall Envelope Approach
E N E R G Y
C O D E S
Tailored Method. This method involves determining
illuminance categories and corresponding lighting power
density values (watt/ft2) for each task space in the building.
Like the other methods, the lighting power density values
are multiplied by the floor area, however, in this case they
are broken down by tasks rather than by use classification.
This approach involves comparing the overall heat transfer of
the proposed building envelope in comparison to the overall
heat transfer for a standard building. The materials in the
7.6
Low-Rise Residential Buildings
standard building calculation would comply with the tabulated
To comply with the CEC, low-rise residential buildings must
prescriptive requirements whilst the materials in the proposed
meet the mandatory requirements and also meet additional
building calculation can be selected to suite the design.
requirements, by using either a performance or prescriptive
approach. See Figure 22.
Space-conditioning systems
space-conditioning systems and equipment must be designed
and selected either by calculation or a computer program
Figure 22
approved by the Commission. This is to ensure that the
California Energy Code compliance
routes for low-rise residential buildings
equipment is appropriately sized for the design loads and in
particular, that the equipment is not oversized which would
lead to it being inefficient. The CEC specifies the various
Compliance for low-rise residential buildings
design parameters that must be considered.
Mandatory Provisions include -
SWH Systems
Insulation
Fireplaces
Space-conditioning equipment
Lighting
There are no additional requirements to the mandatory
requirements already in the code.
Lighting Systems
A buildings lighting power density must not exceed the
allowable power density as calculated by one of three
methods. Lighting systems covered include permanent
Prescriptive Approach
Performance Approach
Tabular prescriptive requirements
and Alternative Componant
Packages
Annual Energy
Budget Method
lighting, track and flexible lighting systems, display lighting and
lighting integral with furniture. However, lighting for certain
functions or occupancies is excluded such as for theme and
amusement parks, film and video studios, medical purposes
and exit and emergency lighting.
The three methods for determining the allowable power
density are:
■
Complete building method. This involves treating the
7.6.1 Mandatory provisions
entire building as a single generic use classification. The
Sub-chapter 7 of the CEC contains the mandatory
allowable power density for the building is determined by
requirements for low-rise residential buildings. These include:
multiplying the conditioned floor area of the entire building
■
Ceiling, wall and floor insulation where the ceiling, wall
or floor separate conditioned spaces from unconditioned
spaces. Insulation must be of the specified R-value.
■
Any open fireplaces having -
by a lighting power density factor specified in a table.
High-rise residential buildings, hotels and motels cannot
use this method.
■
Area category method. This method is similar to the
- dampers;
- designs that draw outside air into the fire box; and
- closable doors covering the entire opening of the
fireplace.
Complete building method but the lighting power density
factors are available for more specific uses within the
building. Conditioned floor areas for each use are
multiplied by the appropriate factors and the sum of
41
the results is the total allowable lighting power density.
■
Infiltration and vapour barriers.
I N T E R N AT I O N A L
■
S U R V E Y
Determining the size of the SPACE-CONDITIONING
equipment using the design heat loss and design heat
gain method as outlined in the ASHRAE Handbook or
an equivalent.
After the mandatory provisions have been met, a building must
comply with either a performance approach or a prescriptive
approach.
O F
B U I L D I N G
E N E R G Y
C O D E S
Assumptions and default values for the calculations are
provided in the code or reference documents for certain
components such as indoor temperatures, occupancy loads,
equipment loads, interior heat transfer, solar heat gains and
losses, etc.
The calculation procedure requires that the energy needed
for cooling be determined even if the building plans do not
7.6.2 Performance approach
indicate any air-conditioning. The total annual energy budget
The performance approach for low-rise residential buildings
is based on calculating the annual energy budget for the
proposed building and ensuring that it is no greater than the
maximum combined allowable energy budget. Energy use
takes into account only the energy used for space
conditioning and SWH systems and only energy from
depletable energy sources. Solar power and non-depletable
sources of energy are exempt from the calculations.
must include the energy that could be needed for comfort
heating, comfort cooling, ventilation for the health the
occupants and water heating.
7.6.3 Prescriptive approach
(Alternative Component Package)
The prescriptive approach provides a table format for the
characteristics needed in specific building components.
Energy use is expressed in terms of kBtu per square foot
per year.
The performance approach is the same as the performance
approach for non-residential, high-rise residential and
hotel/motel buildings except, in this instance, lighting energy
is not included.
The likely energy use of a proposed building may exceed the
energy budgets of either the SWH or the space-conditioning
system as long as the combined usage of the two systems
does not exceed the total of the allowable energy budgets.
They are provided for each climate zone. See Figure 23
for an example.
The building components are:
■
the building envelope with the R-values for the insulation
of ceilings, walls and floors;
■
glazing, covering - maximum U-values;
- maximum glazing area (% of external wall area);
- total non-south facing glazing area;
7.6.2.1 Determine the allowable energy budget
For water heating systems, two calculation formulas are
provided. One for dwelling units having a floor area 2500 ft2
or less and the other for floor areas over 2,500 ft2. These
calculations only take into account the building's conditioned
floor area. Note that other calculation methods can also be
used if approved.
- minimum south facing glazing area;
■
solar heat gain coefficients for south, north, east and
west facing glass;
■
thermal mass characteristics;
■
infiltration control including air barriers and air tight air
heat exchangers;
To determine the allowable energy budget for spaceconditioning systems, computer programs, point systems
or calculation methods can all be used but must be approved
by the Commission.
42
■
space heating systems covering - whether electric space heating can be used;
- the Annual Fuel Utilisation efficiency (AFUE) which
7.6.2.2 Determine the annual energy budget
is the measure of the percentage of heat from the
Using an approved computer program or calculation method,
the annual energy budget is determined taking into account:
combustion of gas or oil, which is transferred to the
■
the orientation of the building;
■
the envelope parameters and glazing areas of the building;
■
the energy conservation features of all building
components;
■
the characteristics of the actual water heating and
space-conditioning systems; and
■
the climate zone.
space being heated;
- the energy efficiency ratings of heat pumps, etc;
■
space cooling system, covering - split systems;
- single package systems;
■
domestic water heaters covering energy efficiency rating
and any credits for using passive design principles or solar
energy systems.
I N T E R N AT I O N A L
S U R V E Y
Within each table there are four Alternative Component
Packages (A to D) available. Each package provides alternative
values for the building components specified above. These
optional packages allow a designer to chose the package
that suits the design and so achieves some flexibility within
a prescriptive approach. For example, greater glazing area
may be traded for an increased insulation R-value.
Depending on the zone and the Alternative Component
Package chosen, the requirements for certain components
may not apply.
Package A is a passive solar design requiring a significant
amount of south-facing glazing, a small amount of non-south
facing glazing, and heavy thermal mass.
Package B allows for a small area of glazing, with light
and heavy mass wall alternatives, whilst some zones require
infiltration barriers and air-to-air heat exchangers.
Package C is the only package that allows electric resistance
space heating. Package C may only be used if the building
is in a location where natural gas is not currently available.
Package D allows more glazing area in some locations
than the other packages but with higher insulation levels.
O F
B U I L D I N G
7.7
E N E R G Y
C O D E S
All Buildings - Mandatory Provisions
The CEC has requirements for the manufacture, construction,
performance and installation of certain systems, equipment
and building components that are installed in all buildings.
These mandatory provisions are additional to the compliance
paths and their respective requirements (including the category
specific mandatory ones) for the two categories of buildings,
ie, (a) low-rise residential buildings and (b) non-residential,
high-rise residential and hotel/motel buildings.
The systems, equipment and building components covered are:
■
any appliance regulated in California under the Appliance
Efficiency Regulations;
■
space conditioning systems and equipment;
■
water heating systems and equipment;
■
pool and spa heating systems and equipment;
■
gas appliances;
■
doors, windows and fenestration products;
■
joints and other openings;
■
insulation; and
■
lighting control devices.
Figure 23: Prescriptive requirements for residential buildings
TABLE 1-Z1—ALTERNATIVE COMPONENT PACKAGES FOR CLIMATE ZONE 1
43
COMPONENT
BUILDING ENVELOPE
Insulation minimums2
Ceiling
Wood-frame walls
"Heavy mass" walls
"Light mass" walls
Below-grade walls
Slab floor perimeter
Raised floor
Concrete raised floors
GLAZING
Maximum U-value3
Maximum total area
Maximum total nonsouth-facing area
Minimum south-facing area
SOLAR HEAT GAIN COEFFlClENT4
South-facing glazing
West-facing glazing
East-facing glazing
North-facing glazing
THERMAL MASS5
INFILTRATION CONTROL
Continuous barrier
Air-to-air heat exchanger
SPACE-HEATING SYSTEM6
Electric-resistant allowed
If gas, AFUE =
If heat pump,
split system HSPF8 =
Single package system HSPF =
SPACE-COOLING SYSTEM
If split system A/C, SEER =
If single package A/C, SEER9 =
DOMESTIC WATER-HEATING TYPE
System must meet budget, see Section 151 (b) 1 and (f) 9
A
B
PACKAGE 1
C
D
R30
R19
(R8.5)
(R8.5)
NA
R7
R19
NA
R30
R19
(R5.0)
(R6.0)
NA
R7
R19
NA
R49
R29
NA
NA
NA
R7
R30
NA
R38
R21
(R4.76)
NA
RO
NR
R193
R8
0.65
NR
9.6%
6.4%
0.65
16%
NR
NR
0.40
14%
NR
NR
0.65
16%
NR
NR
NR
NR
NR
NR
REQ
NR
NR
NR
NR
NR
NR
NR
NR
NR
REQ
NR
NR
NR
NR
NR
NR
NR
REQ
REQ
NR
NR
NR
NR
No
78%
No
78%
Yes7
78%
No
MIN
6.8
6.6
6.8
6.6
6.8
6.6
MIN
MIN
10.0
9.7
10.0
9.7
10.0
9.7
MIN
MIN
Any
Any
Any9
Any
Legend: NR = Not required; NA = Not applicable; REQ = Required; MlN = Minimum
See notes following Table l-Z16.
I N T E R N AT I O N A L
S U R V E Y
For the compliance of space conditioning equipment,
there is energy efficiency ratings (EER) of space conditioning
O F
B U I L D I N G
C O D E S
Requirements include:
■
equipment, combustion efficiency of boilers and thermal
all products being tested to demonstrate compliance
with maximum air leakage rates;
efficiency of furnaces. The relevant test standard is
also stated.
E N E R G Y
■
all products being certified as achieving a specified
U-value in accordance with relevant standards and
Appliance Efficiency Regulations.
Table 1-D of the CEC; and
These regulations require that any appliance must be
certified by the manufacturer for compliance with the
■
caulked and weather-stripped.
Californian standards established in the Appliance Efficiency
Regulations. This includes space conditioning equipment
units that are fabricated on site being adequately
Joints and other openings
and water heating systems.
Joints and other openings in the building envelope that
Other space conditioning equipment
are potential sources of air leakage must be caulked and
All equipment must meet the energy efficiency requirements of
weather-stripped.
Table 1-C of the CEC and also must have controls to ensure
that heat pumps do not run unnecessarily such as when the
heating load is low.
Insulation
Insulation products must be certified by the manufacturer as
complying with the relevant standards. In addition, insulating
Other service water heating systems and equipment
material must achieve the necessary fire-spread rating and
Specific requirements include:
smoke density.
■
energy efficient equipment;
■
controls on circulating pumps to reduce energy
consumption when hot water is not required;
■
■
Lighting control
The CEC does require the equipment to be provided, just
that if it is, it must be capable of achieving certain functions.
temperature controls for the hot water in public toilet
Equipment includes time switch controlling, occupant-sensing
facilities; and
and daylight sensing.
the insulating of storage tanks.
7.8
Pool and spa heating systems and equipment
Specific requirements include:
■
thermal efficiency of gas fired systems;
■
controls for shut down and time switches for the
Semi-conditioned non-residential buildings
Figure 24 is a flow chart that indicates the energy efficiency
requirements for buildings having full, partial or no space
conditioning. If a building is to have minimal space conditioning,
there are no energy efficiency requirements for the building
operation of circulation pump;
■
no pilot light being permitted; and
■
water surface covers being provided.
envelope, water heating or space-conditioning systems.
The Code only requires such a building to meet the mandatory
requirements for lighting as specified in the relevant section
for:
Gas appliances
■
all buildings - mandatory requirements for lighting; and
Specific requirements include:
■
high-rise residential, non-residential buildings and
■
energy efficient equipment; and
■
no pilot light being permitted.
hotel/motel buildings- mandatory prescriptive requirements
for lighting and equipment.
If there is to be any significant space conditioning, whether
44
Doors, windows and fenestration products
it be direct or indirect, full compliance is generally required.
This includes skylights, curtain walls and sliding glass doors.
The criteria for full compliance is a heating load greater than
Fenestration products includes any transparent or translucent
10 BTU/hr/ft2 or a cooling load less than 5 BTU/hr/ft2 and
material such as a sash, frame, mullion or divider.
space conditioning between 55oF and 90oF.
I N T E R N AT I O N A L
7.9
S U R V E Y
O F
New Construction
In Existing Buildings
B U I L D I N G
E N E R G Y
C O D E S
7.9.1.1 Additions
The envelope, lighting, space conditioning and water heating
equipment for the building addition must comply with the
The CEC has requirements for new construction in
mandatory provisions and either the prescriptive or the
existing buildings in the following categories:
performance approach as described previously.
non-residential, high-rise residential, and hotel/motel
The requirements under the prescriptive approach are only
buildings;
for the new addition.
■
low-rise residential; and
As part of the performance approach, the addition must also
■
semi-conditioned buildings.
■
comply with the annual energy budget method or alternatively
the entire building must be improved to show compliance
to the energy budget method. In the latter case, the new
7.9.1 Non-residential, high-rise residential,
and hotel/motel buildings
building’s anticipated energy consumption is compared to the
The requirements are divided into additions and alterations.
addition must not make the existing building any less efficient.
Figure 24
existing buildings energy usage as if it were unchanged. The
Flow chart for compliance
Yes
Does the heating exceed
10 BTU/hr/ft2? Or does the cooling
system exceed 5 BTU/hr/ft2
Is there a mechanical
heating or mechanical
cooling system?
Yes
No
No
Is there evaporative cooling,
wood heating or a non-depletable
energy source used for space
The space is semi-conditioned
and must comply with
lighting requirements
Yes
Is the temperature maintained for
a process environment outside
the range of 55˚F through 90˚F?
Yes
No
Is the space indirectly
conditioned
(defined term)
Full compliance with the
standards (envelope, lighting
and mechanical) is required?
OR
Yes
Is the space conditioning system
designed and controlled to be
incapable of operating at temperatures
above 55˚F or incapable of operating
at temperatures below 90˚F at
design conditions?
Yes
45
No
No
No
Full compliance with the
standards (envelope, lighting
and mechanical) is required?
I N T E R N AT I O N A L
S U R V E Y
7.9.1.2 Alterations
O F
B U I L D I N G
■
C O D E S
for areas up to 100 ft2, glazing area cannot exceed
50 ft2 and a glazing U-value of 0.75;
This covers changes in the buildings use or occupancy as
well as physical changes to the structure. Again, the buildings
E N E R G Y
■
must comply with the mandatory provisions as well as either
for areas greater than 100 ft2 but not exceeding 1000 ft2,
the addition must meet the requirements of Alternative
the prescriptive or the performance approaches.
Component Package D under the appropriate table
Under the prescriptive approach it must be demonstrated
with some exceptions;
that the alterations to the building envelope■
■
do not increase the overall heat gain or loss; and
■
meet the prescriptive requirements of either the envelope
component approach or the overall envelope approach.
requirements of Alternative Component Package D under
the appropriate table without exceptions.
Again, under the performance approach, the alterations must
Under the performance approach, the alterations must comply
comply with the annual energy budget method or the entire
with the annual energy budget method or the entire building
building must be improved to show compliance to the energy
must be improved to show compliance to the energy budget
budget method. In the latter case, the altered building’s energy
method. In the latter case, the altered building’s energy usage
is compared to the existing buildings energy usage as if it
were unchanged. Again, the addition must not make the
existing building any less energy efficient.
7.9.2 Low-rise residential buildings
Once again, the requirements are divided into additions
and alterations.
7.9.2.1
46
for areas exceeding 1000 ft2, the addition must meet the
Additions
usage is compared to the existing buildings energy usage as
if it were unchanged. Again, the addition must not make the
existing building any less energy efficient.
7.9.2.2 Alterations
Again, the approach is the same as for Non-residential,
high-rise residential, and hotel/motel buildings.
7.9.3 Semi-conditioned buildings
The approach is the same as for Non-residential, high-rise
Requirements for new semi-conditioned buildings only
residential, and hotel/motel buildings. The requirements under
cover lighting and generally, the lighting to the new portion
the prescriptive approach depend on the floor area of the
of the building, or the portion altered, need only comply
addition, for example:
with the mandatory requirements of the CEC.
SECTION EIGHT
HAWAII
I N T E R N AT I O N A L
SECTION 8
8.1
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
HAWAII
Regulatory Framework
In the USA, building control is the responsibility of the
individual States and, in many cases under the control of
the smaller counties within the State. The States and, where
permitted, the counties may adopt any form of regulation
or standard of construction they consider appropriate.
The State of Hawaii Model Energy Code has developed it’s
own requirements for residential buildings. For other buildings,
There are some exceptions to the requirements described
above including where innovative natural ventilation schemes
are used to provide air movement or to provide in some
other way comfortable temperature and humidity conditions.
Approved must be based on demonstration or analysis.
Habitable rooms in houses that do not fully satisfy the
natural ventilation requirements must be wired for the
future installation of ceiling fans complete with wall-mounted,
variable-speed fan controls.
its requirements have been adapted mainly from ASHRAE/IES
90.1-1989 Energy Efficient Design of New Buildings Except
When air conditioning is installed, there are additional
Low-Rise Residential Buildings. It has also been influenced
requirements for equipment efficiency, wall insulation or
by the most recently adopted California codes (Title 24),
shading, window tinting or shading, and air leakage.
ASHRAE/IES 90.2P and the USDOE standard for nonresidential buildings. In addition, many parts of the Code have
8.4
Air Leakage
been developed specifically for the unique conditions of the
Air leakage requirements apply to all air-conditioned spaces.
Islands, in particular the requirements for natural ventilation.
They prohibit the cooling of unenclosed spaces except under
The Hawaii Model Energy Code is not dealt with in depth as
certain conditions. They also require tightly closing windows
it is similar other USA codes previously covered. Instead, the
and doors, self-closing or revolving commercial entrance
report deals with those requirements that are unique and are
doors and sealing of cracks and holes. A designer might
of particular relevance to Australian environmental conditions.
consider meeting these requirements even for an
unconditioned building in order to avoid potentially costly
8.2
Ceiling Heat Gains
upgrades if air conditioning might be added in the future.
Ceilings must either be insulated or alternatively may use
Air conditioned spaces must be enclosed. The space must
a radiant barrier in combination with a light-coloured roof.
be separated from the outside by roofs, ceilings, walls, floors,
The requirement is expressed as a maximum roof heat gain
doors and/or windows. If a space has a window or door that
factor (RHGF).
is normally open during operating hours, then it is considered
unenclosed. Open-air hotel lobbies and restaurants or retail
8.3
Natural Ventilation
spaces, which normally keep their doors open, are examples
of unenclosed spaces.
The requirements for a naturally ventilated house are intended
to eliminate the need for air conditioning. In addition to roof
heat gain requirements, habitable rooms (kitchens, bedrooms,
living areas and dining rooms) must have two operable
openings on opposite or adjacent walls to provide cross
ventilation. Alternatively, they may be on opposite sides of
weather-stripped or otherwise tightly sealed to minimise air
leakage. Openings such as jalousie windows, which cannot
be tightly sealed, are allowed, but they may not account for
more than two percent of the exterior wall area.
a wing wall. Their minimum free ventilation area must be at
Commercial entrances that enclose conditioned space
least 12% of the floor area. In addition, louvres or door
must have self-closing or revolving doors.
catches must be installed on interior doors.
48
Doors and windows enclosing conditioned space must be
Finally, exterior joints, cracks and holes in and between the
For other classes of buildings, there is a requirement that
walls, ceilings and floors which enclose conditioned space
no more than 70 percent of the total opening area may be
must be caulked, gasketed, weather-stripped or otherwise
placed on one wall (or on one side of a wing wall).
sealed to prevent air leakage.
I N T E R N AT I O N A L
8.5
S U R V E Y
Swimming Pools and Spas
Pools and spas have several requirements. Any heating must
be by solar means or by heat pump with the heater meeting a
minimum thermal efficiency and heat pumps and their pumps
must be provided with on/off controls and a time switch.
Gas or electric resistance pool heating is allowed only if it
can be shown to provide lower annual energy costs than
the solar or heat pump systems.
8.6
Testing, Operation and
Maintenance Information
Commercial buildings must have:
■
energy management capability;
■
testing and balancing; and
■
operating and maintenance manuals.
8.7
Economic Calculations
For some of the Code’s requirements, there are exceptions
based on economic calculations. The life cycle costing method
is specified and takes into account the equipment installation
cost, the maintenance costs and the energy costs over the
lifetime of the equipment. The Code also indicates that a real
discount rate of 3% is typical for energy policy analyses while
higher rates are often used by private investors for commercial
construction.
The U.S. Department of Energy has proposed a 4.5%
discount rate for federal agency in-house energy management
programs. This rate is calculated from the long-term bond rate
(8.5% at the time) minus the inflation rate (4%).
49
O F
B U I L D I N G
E N E R G Y
C O D E S
SECTION NINE
CANADA
I N T E R N AT I O N A L
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
SECTION 9 CANADA
9.1
The model codes cover the main systems and components
Regulatory Framework
In many ways the Canadian building control system is
similar to the Australian system. The Canadian Provincial
and Territorial Governments, like the Australian States and
of a building, namely the building envelope, lighting, HVAC
systems, SWH heating and electrical power system.
Requirements vary depending on the type of building, the
systems incorporated in the building, the climate zone and
Territories, have jurisdiction over building control.
ultimately the path chosen for compliance.
The National Research Council (NRC) of Canada is the
equivalent of the ABCB to the extent that they formulate
The requirements for building envelope and HVAC systems
national codes for possible adoption by the Provinces and
are only applicable if the building has conditioned (heated
Territories. However, the ABCB does not publish model
or cooled) space. In this case, the philosophy is to reduce
codes, only nationally agreed and nationally applied codes.
the energy flow between the building and the environment.
The NRC has developed the following two model energy
efficiency codes:
■
the Model National Energy Code of Canada for
The requirements for electrical power, lighting and SWH
apply generally to all buildings with some minor exemptions.
As the Provinces and Territories have responsibility for building
control, they also have the power to decide which codes to
Houses - 1997 (MNECH); and
adopt. Figure 25 indicates the current status of energy codes
■
the Model National Energy Code of Canada for
adopted in the jurisdictions of Canada.
Buildings - 1997 (MNECB).
This report will cover the Model National Energy Codes
These two model codes set out minimum requirements
for energy efficiency measures in buildings. The requirements
are, for the most part, based on extensive cost-benefit
Code will be reviewed as an example of a provincial code.
analysis that take into consideration climate, fuel types
Figure 26 illustrates the structure and compliance routes
and costs and construction costs.
for both the MNECH and the MNECB.
Figure 25
Status of energy codes adopted in the Provinces of Canada
Province
51
developed by the NRC. In addition, the Ontario Building
Residential
Commercial
Code
Application
Code
Application
British Columbia
Model National Energy
Code for Houses
City of Vancouver only
MNECB
City of Vancouver - all buildings.
Provincial adoption for Govt buildings.
Alberta
Alberta Building Code
Minor requirements for insulation.
Requirements less than MNECH
None
Saskatchewan
None
Manitoba
Manitoba Building Code
Similar to MNECH
None
Reviewing MNECB for public buildings
Ontario
Ontario Building Code
Separate requirements. Insulation
requirements for the building
envelope similar to the MNECH
MNECB or ASHRAE/IES 90.1
All buildings
Quebec
Separate regulations
No current information
Separate regulations
No current information
New Brunswick
No current information
Nova Scotia
Model National Energy
Code for Houses
None
No current information
All
MNECB
All
Prince-Edward Island
No current code
Adoption may be at municipal level
No current code
Adoption may be at municipal level
Newfoundland
No current code
Adoption may be at municipal level
No current code
Adoption may be at municipal level
I N T E R N AT I O N A L
9.2
S U R V E Y
O F
E N E R G Y
C O D E S
9.2.2 General provisions
Model National Energy Code
of Canada for Houses - 1997
The Code outlines the general parameters and procedures
used in determining the energy efficiency requirements
including:
9.2.1 Scope
The scope of this code applies to:
■
new buildings of three storeys or less that do not have a
floor area greater than 600m2 and contain only dwelling
units or other ancillary uses;
■
new buildings of residential occupancy containing not
more than one dwelling; and
■
additions of more than 10m2 in floor area to existing
buildings described in (a) and (b).
The MNECH refers to buildings "containing only dwelling units,
related ancillary service rooms, shared means of egress or
garages serving the units" (Clause 1.1.2.1.1(a)). This rules out
hotels and motels, but includes single-family houses, flats and
apartment buildings within the storey and floor area limitations.
Other building types will fall under the Model National Energy
Code for Buildings.
Figure 26
B U I L D I N G
■
climatic data;
■
the overall thermal transmittance values of materials
from standards or by recognised calculations;
■
the methods for determining solar heat gain coefficients
for windows;
■
the formula for calculating areas and for applying
concessions; and
■
referenced documents.
9.2.3 Mandatory measures
The intended mandatory requirements are detailed for each
of the main building systems and components. They must be
complied with regardless of the compliance path chosen and
so cannot be traded-off. The mandatory requirements are
contained within the section for each building component.
National Model Energy Code compliance routes
GENERAL
MANDATORY PROVISIONS
Envelope
Lighting
Prescriptive path
HVAC
Service Water
Electrical Power & motors
Performance path
MANDATORY PROVISIONS
Prescriptive
requirements
Trade-offs (simple or
computer assisted)
BUILDING ENERGY
PERFORMANCE METHOD
HVAC
LIGHTING
SERVICE WATER HEATING
(for buildings only)
COMPLIANCE WITH NATIONAL MODEL ENERGY CODE
52
I N T E R N AT I O N A L
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
9.2.3.1 Building envelope
Heat traps are required on water heaters and all hot water
Building envelope requirements include:
piping must be insulated. Controls are required so that heaters
■
installation and continuity of insulation;
■
air-tightness of components in the building envelope; and
■
air leakage and energy rating classification of windows
and doors.
operate over a specific temperature range and can be easily
shut down, when not needed such as during vacations.
9.2.3.2 Lighting
There are requirements for both internal and external lighting.
However, the interior lighting requirements in the MNECH is
limited to ancillary rooms shared by the occupants of the
dwelling units such as communal laundries. Internal lighting
in other areas is exempted because it was considered that
the energy consumption of lighting in dwelling units was
not overburdening enough to warrant the type of measures
being put forward and would also be difficult to regulate.
Requirements for houses cover:
Showers are required to have a maximum water discharge
head, swimming pools must have controlled heaters and
pumps and heated pools are required to have covers.
9.2.3.6 Electrical power
The MNECH has mandatory requirements to assist the
managing of electrical power including the metering of
power to individual dwelling units.
9.2.4 Prescriptive path
As shown in Figure 26, there two compliance paths available
for the designer; the prescriptive and performance path. The
prescriptive path for housing only covers the building envelope
and the HVAC system.
■
exterior lighting and including- minimum luminous efficacy of not less than 40 lm/W;
- maximum power densities;
- lighting controls;
■
interior lighting to common areas and including- requirements for fluorescent lamp ballasts; and
- lighting controls.
There are two optional procedures available for the building
envelope to meet the requirements. These are:
■
the Prescriptive Method; and
■
the Trade-off Method.
Interior lighting requirements are much more extensive
in the MNECB.
Prescriptive Method
9.2.3.4 Heating, ventilation and HVAC systems
specified in Section 3.3 of the MNECH. This clause refers to
The MNECH has requirements for HVAC systems serving
a single dwelling unit. For systems serving multiple dwellings,
the MNECB must be used.
Appendix A of the MNECH that details the minimum effective
Mandatory requirements include equipment and system
performance and the controls needed to operate the
system efficiently.
9.2.3.5 SWH systems
The mandatory provisions for SHW systems covers
installation details and controls.
53
9.2.4.1 Building envelope
The system design must be in accordance with Provincial,
Territorial or municipal building regulations, or the National
Plumbing Code of Canada 1995. The efficiency of storage
vessels and heating equipment must also be in accordance
with Federal, Provincial or Territorial Acts, with local regulations
or with a table in the code. These limit the manufacture and
sale of equipment that does not meet the minimum efficiency
requirements stated in a series of standards. The energy
codes avoid possible conflicts by not duplicating these acts;
rather, it references them. The table is for localities outside the
jurisdiction of the Acts or regulations.
The prescriptive requirements for the building envelope are
thermal resistance (RSI-value, m2 .˚C/W) of the roofs, walls
and floors for each climatic region and for each principal
heating source. This is in table format. Figure 27 is an extract
of the table from the MNECH for the Ontario Region A.
Figure 27 also shows the requirements for windows and
doors expressed as a minimum energy rating (ER) in W/m2.
An ER rates a windows in terms of its combined response
to solar heat gain, conductive heat loss and air leakage.
It is based on the total performance of the element
including the sash, frame, etc.
I N T E R N AT I O N A L
Figure 27
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
Example of prescriptive tables in the MNECH
ONTARIO Region A- < 5000 Degree-days
Table A-3.3.1.1. Prescriptive Requirements - Above ground Building Assemblies Forming Part of Sentence 3.3.1.1.(1)
Assembly Description
Roots (See Appendix Note A-3.3.1.1.):
Type I
– attic-type roofs
Type II
– all other roofs (e.g., sawn lumber joists,
parallel-chord trusses and wood I-joists)
Walls
Floors
Principal Heating Source
Electricity, Other
Propane, Oil, Heat Pump
Natural Gas
Minimum Effective Thermal Resistance (RSI-value), m2 °C/W
8.80
5.20
7.00
4.30
5.60
4.30
4.40
5.20
3.00
4.50
2.90
4.50
Table A-3.3.1.3. Prescriptive Requirements - Windows and Other Glazed Areas Forming Part of Sentence 3.3.1.3.(1) and (2)
Electricity, Other
Assembly Description
Windows and sliding glass doors within the scope of
CSA Standard A440.2 (See Appendix Note A-3.3.1.3.):
Operable or fixed glazing with sash
Fixed glazing without sash
Windows and other glazed areas outside the scope of CSA
Standard A440.2
Principal Heating Source
Propane, Oil, Heat Pump
Minimum Energy Rating (ER), W/m2
Natural Gas
-10.0
0.0
-13.0
-13.0
-3.0
-3.0
Maximum Overall Thermal Transmittance W/m2. °C
2.40
2.60
2.60
As part of these requirements, windows cannot exceed
9.2.4.2 HVAC system
20% of the floor surface area of the building although some
The MNECB only applies to a HVAC system serving a single
compensatory measures are possible for large areas.
dwelling unit and the prescriptive requirements only cover
heat recovery. A mechanical exhaust system must be fitted
Trade-off Method
with a device to transfer the heat from the air being exhausted
The MNECH permits two means of carrying out a trade-off.
to the fresh air entering the building. It must have a heat
recovery efficiency as specified in a table and the efficiency
Simple trade-off
varies depending on the outdoor design temperature at the
This procedure permits the effective thermal resistance of one
building’s location.
or more components of the building envelope to be less than
the prescriptive requirements of Section 3.3 (Appendix A
Heat recovery is also required for enclosed swimming
pools with details being given in the MNECB.
Tables) provided the effective thermal resistance of the other
components is increased. The final design is acceptable if the
9.2.5 Performance path
sum of the areas of all components of the building envelope,
9.2.5.1 Building Energy Performance Method
divided by their respective effective thermal resistances, is
not more than it would be if the components complied totally
This method can be used as an alternative to the prescriptive
path for the building envelope and HVAC systems.
with Section 3.3.
Firstly, the mandatory requirements must still be met. Any
Computer assisted trade-off
extra efficiency in meeting these mandatory requirements
An alternative to a compliant calculation is to use software
cannot be used as trade-offs in the performance compliance
detailed in a NRC publication titled Trade-off Compliance
54
calculations, other than for the efficiency of HVAC equipment.
for Houses: Specifications for Calculation Procedures for
The performance path is based on the premise that the
Demonstrating Compliance to the Model National Energy
building does not have to comply with the prescriptive
Code for Houses Using Trade-offs.
requirements provided it can be shown, using approved
I N T E R N AT I O N A L
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software, that the building will not use more energy in a
and calculation methods to those of the housing code.
typical year than it would if it were to comply with the
The mandatory provisions are in the respective sections for
prescriptive requirements.
each building component. They are generally similar to the
This approach permits each building to have a custom-made
energy budget or target. This target is based on a building
similar to the one under consideration, but fully complying
with the Code’s prescriptive requirements.
There are some limits as to what can be traded off using
this method. For example, the effective thermal resistance
MNCEH but there are some differences.
9.3.1 General provisions
The MNECB outlines the general parameters and
procedures used in satisfying the energy efficiency
requirements. These include:
■
climatic data;
■
the overall thermal transmittance values of materials
of opaque components of the building envelope can not be
reduced below a certain level of their prescriptive requirements
from standards or by recognised calculations;
eg. 75% for walls and 60% for other elements.
Lighting and HVAC systems are included in the computer
■
for windows;
analysis.
A further consideration is the energy costs of various heating
■
the formula for calculating areas and for applying
concessions; and
energy sources, eg. gas, oil, electricity. To compensate for
this, the differences in energy costs of the various heating
the methods for determining solar heat gain coefficients
■
referenced documents.
energy sources have been taken into account in the regional
requirements. This results in variations in insulation requirements
for the different energy sources in each region. An energy
9.3.2 Mandatory measures
9.3.2.1 Building envelope
source adjustment factor for each energy source is provided
in an Appendix of the code.
The intended mandatory requirements are detailed for each
of the main building systems and components. They must
The calculations for this method of compliance must be
be complied with regardless of the compliance path chosen
carried out using software that conforms to specifications
and so cannot be traded-off. The mandatory requirements
found in Performance Compliance for Houses: Specifications
are contained within the section for each building component.
for Calculation Procedures for Demonstrating Compliance to
As for houses, the requirements cover:
the Model National Energy Code for Houses Using Whole
House Performance.
9.3
Model National Energy Code
of Canada for Buildings - 1997
This code applies to all new buildings and additions to existing
buildings not covered by the MNECH. It includes residential
■
installation and continuity of insulation;
■
air-tightness of components in the building envelope; and
■
air leakage and energy rating classification of windows
and doors.
These provisions are very similar to the general provisions
for housing.
buildings more than three storeys high and all commercial,
industrial, manufacturing and public buildings. It exempts
9.3.2.2 Lighting
buildings less than 10m2 and farm buildings.
As well as having mandatory provisions for interior and exterior
Generally, the code has requirements for:
lighting characteristics and controls there are also provisions
for entrance and exit lighting and facade lighting. Display
■
the building envelope;
■
HVAC systems;
high-risk security lighting are all exempt from the requirements.
■
SWH systems;
9.3.2.3 HVAC systems
■
lighting systems; and
Mandatory requirements take a similar form to those for
■
electrical power systems but excluding process loads.
Figure 26 illustrates the structure of the MNECB for buildings
as well as the MNECH for houses.
55
The general requirements include similar provisions
lighting for landscape, lighting of monuments and signage and
houses, however, there are more detailed procedures involved
such as testing duct for air leakage.
There are requirements for the design of HVAC pumping
systems that have pump motors of 7.5 kW or over. There
are requirements for temperature controls such as shut down
I N T E R N AT I O N A L
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means and set point adjustment. There are also minimum
performance requirements for equipment including airconditioners, condensing units, water chillers, boilers,
furnaces and heaters.
9.3.3 Prescriptive path
9.3.2.4 SHW systems
paths that may be used to meet the requirements for the
Similar to houses, requirements include the efficiency of
storage vessels, insulation of piping and temperature controls.
There are also restrictions on water flow to sanitary facilities
such as showers.
9.3.2.5 Electrical power
The MNECB requirements aim to achieve efficient use
of energy by electric power systems. Metering is required
for individual occupancy units and suites according to the
Canadian Regulations relating to the inspection of Electricity
and Gas Meters and Supplies. More extensive monitoring
facilities are also required for distribution systems whose
load-carrying capacity is greater than 250 kVA.
9.3.3.1 Building envelope provisions
As with the housing code, there are two alternative compliance
building envelope. These are:
■
the Prescriptive Method; and
■
the Trade-off Method.
Prescriptive method
The prescriptive requirements for building envelopes are similar
to those for housing and are specified in Section 3.3 of the
MNECB. This clause refers to Appendix A of the MNECB,
which details the minimum effective thermal resistance (RSIvalue, m2 .oC/W) of the roofs, walls and floors for each climatic
region and for each principal heating source. This is in table
Building transformers are required to conform to Federal,
Provincial or Territorial Acts and Regulations.
format. Figure 28 is an extract of the table from the MNECB
As for the MNECH, equipment efficiencies are also
covered by the Federal and Provincial/Territorial energy
efficiency Parliamentary Acts. These limit the manufacture
and sale of equipment to that does not meet the minimum
efficiency requirements.
There are extra requirements for vestibules, such as equipping
The energy codes avoid possible conflicts by not duplicating
these acts; rather, it references them.
other glazed elements to have an energy rating (ER), building
Finally, electrical motors must be of the minimum efficiency
stated in Canadian standards.
transmission. This is a measure of the rate at which heat is
Figure 28
for British Columbia, Region B.
doors with self-closers, or providing an airlock with two doors.
In addition, the provisions for windows and other glazed areas
are slightly different. Whilst housing required windows and
fenestrations are required to have a maximum overall thermal
transferred through glazed. Refer to Figure 29.
Example of prescriptive tables in the MNECB for building envelopes
Table A 3.3.1.1.(1) Prescriptive Requirements - Above-ground Building Assemblies Forming Part of Sentence 3.3.1.1.(1)
Principal Heating Source
Electricity, Other
Propane, Oil, Heat Pump
Natural Gas
BC Gas II PNG
Assembly Description
Maximum Overall Thermal Transmittance (U-value), W/m2 °C
Roots (See Appendix Note A-3.3.1.1. (1)):
Type I
- attic-type roofs
0.140
0.140
0.180 II 0.140
Type II
- parallel-chord trusses and joist-type roofs
0.230
0.230
0.230 II 0.230
Type III
- all other roofs (e.g., concrete decks with rigid insulation)
0.290
0.290
0.470 II 0.410
0.370
0.370
0.450 II 0.450
Walls
Floors
56
Type I
- parallel-chord trusses and joist-type roofs
0.220
0.220
0.220 II 0.220
Type II
- all other roofs (e.g., concrete decks with rigid insulation)
0.290
0.290
0.470 II 0.410
I N T E R N AT I O N A L
Figure 29
S U R V E Y
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Example of prescriptive tables in the MNECB for glazed areas
Table A-3.3.1.2. Prescriptive Requirements - Fenestration(1) Forming Part of Sentence 3.3.1.2.(1)
Principal Heating Source
Assembly Description
Fenestration-to-Wall Ratio
Electricity, Other
Propane, Oil, Heat Pump
Natural Gas
Maximum Overall Thermal Transmittance (U-value), W/ m2 °C
Fixed Glazing without Sash
up to 0.4
> 0.4 to 0.5
> 0.5 to 0.6
> 0.6 to 0.7
> 0.7 to 0.8
> 0.8 to 0.9
>0.9
1.70
1.60
1.50
1.50
1.40
1.40
1.40
1.70
1.60
1.50
1.50
1.40
1.30
1.30
3.20
2.90
2.60
2.40
2.30
2.10
2.00
Operable or Fixed Glazing with Sash
up to 0.4
> 0.4 to 0.5
>0.5 to 0.6
>0.6 to 0.7
> 0.7 to 0.8
> 0.8 to 0.9
> 0.9
2.70
2.40
2.20
2.10
2.00
1.90
1.80
3.40
3.00
2.70
2.50
2.30
2.20
2.10
3.40
3.00
2.70
2.50
2.40
2.20
2.10
Trade-off method
Like for housing, the MNECB requires that the mandatory
The trade-off method outlined for buildings is similar to those
requirements for the envelope and lighting, HVAC and SHW
for houses with a simple approach and a computer assisted
systems be met. It then requires that the annual adjusted
approach.
energy consumption of the building be calculated and be
9.3.3.2 HVAC, lighting and SHW system
compared to an energy target for the building. Once again, the
performance path is based on the premise that the building
Lighting
does not have to comply with the prescriptive requirements
The prescriptive compliance path gives methods for
provided it can be shown, using approved software, that the
calculating interior lighting power allowances and densities
building will not use more energy in a typical year than it
for individual building types.
would if it were to comply with the prescriptive requirements.
HVAC system
The prescriptive compliance path not only has requirements
for air-to-air heat recovery similar to those for houses, but
also has requirements for the design of fan systems, outdoor
air cooling systems and automatic control system.
This approach permits each building to have a custom-made
energy budget, or target. This target is based on a building
similar to the one under consideration, but fully complying
with the Code’s prescriptive requirements.
The calculations for this method of compliance are to be
carried out using software that conforms to specifications
SWH systems
There are also requirements for boilers, calorifiers, etc. used
to provide space heating and service water heating.
57
found in "Performance Compliance for Buildings:
Specifications for Calculation Procedures for Demonstrating
Compliance to the Model National Energy Code for Buildings
9.3.4 Performance path
Using Whole Building Performance."
9.3.4.1 Building energy performance compliance
Different energy sources are taken into account in the building
This path provides a means of complying other than the
energy performance method using the Energy Source
prescriptive path. It covers the building envelope and the
Adjustment Factor. This takes into account different Provinces
HVAC, lighting and SWH systems. This is similar to that
and regions within each Province and the different energy
for houses except that lighting and SWH can be included.
sources, ie. electricity, propane, oil, natural gas, etc.
SECTION TEN
C A N A D A - O N TA R I O
I N T E R N AT I O N A L
SECTION 10
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
C A N A D A - O N TA R I O
10.1 Regulatory Framework
This grouping is because they have similar requirements
The Province of Ontario has responsibility for building control
in it’s own jurisdiction and so has its own building code called
for the structure, fire protection, etc. However only residential
buildings have energy efficiency requirements. These residential
the Ontario Building Code 1997. The Ontario Building Code
buildings include sleeping accommodation in single residences,
contains unique energy efficiency requirements rather than
multi family residences (flats and apartments) and hotels and
referencing the MNECH or the MNECB. However, the code
motels within the storey and floor area limitation. It does not
does reference the MNECB as one compliance option for
include nursing homes/hostels or detention centres.
buildings (other than houses and small buildings).
The Ontario Building Code specifies two prescriptive
The Ontario Building Code has energy efficiency requirements
approaches for complying.
for two categories of buildings. These are:
Section 9.25 has requirements for the thermal insulating
■
houses and small buildings; and
material and their installation in all walls, ceilings and floors
■
other buildings.
separating heated and non-heated spaces. These requirements
are in the form of R-values, which vary between two main
10.2 Houses and Small Buildings
climate zones. The climate zones are for locations with less
than 5,000 heating degree-days per year and 5,000 or more
The Ontario Building Code combines the requirements
for housing and small buildings and applies them to buildings
heating degree-days per year. The R-values are greater if the
of three storeys or less, having a floor area not exceeding
building has electric space heating. The R-values as specified
600 m2 and used for:
in tabular form. Figure 30 shows Table 9.25.2.1 of the Ontario
Building Code that gives the minimum thermal insulation
■
residences;
■
business and personal services;
■
displaying or selling goods, wares or merchandise; and
■
medium and low hazard industry.
resistance values for building elements.
Glazing that separates heated space from unheated
Figure 30
space must have a thermal resistance of not less than
0.30 m2 ºC/W.
Table for the minimum thermal resistance insulation required to building elements
Table 9.25.2.1. Minimum Thermal Resistance of Insulation to be Installed based on Degree Day Zones(1)
Forming Part of Sentence 9.25.2.1.(4)
RSI (R) Value Required
Building Element Exposed to the
Zone 1
Zone 2
Electric Space Heating
Less than 5000
5000 or more
Zone 1 & 2
Ceiling below attic or roof space
5.40 (R31)
6.70 (R38)
7.00 (R40)
Roof assembly without attic or roof space
3.52 (R20)
3.52 (R20)
3.87 (R22)
Wall other than foundation wall
3.00 (R17)
3.87 (R22)
4.70 (R27)
Foundation walls enclosing heated space
1.41 (R8)
2.11 (R12)
3.25 (R19)
Floor, other than slab-on-ground
4.40 (R25)
4.40 (R25)
4.40 (R25)
Slab-on ground containing pipes or heating ducts
1.76 (R10)
1.76 (R10)
1.76 (R10)
Slab-on-ground not containing pipes or heating ducts
1.41 (R8)
1.41 (R8)
1.41 (R8)
2
3
4
Exterior or to Unheated Space
59
Column 1
I N T E R N AT I O N A L
Figure 31
S U R V E Y
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Table 9.38.3.1 for the minimum thermal resistance insulation required to building elements
Maximum Number of Celsius Degree days
Building Assembly
Electric Space Heating
Up to 5000
Above 5000
Ceiling below attic or roof space
5.6(R32)
6.9(R39)
7.20(R41)
Roof assembly without attic or roof space
3.8(R22)
3.8(R22)
4.15(R24)
Wall other than foundation wall
3.45(R19)
4.3(R24)
5.15(R29)
Foundation walls enclosing heated space
1.7(R10)
2.4(R14)
3 54(R20)
Floor, other than slab-on-ground
4.7(R27)
4.7(R27)
4.7(R27)
Slab-onground(1)
— containing pipes or heating ducts
— not containing pipes or heating ducts
2.11(R12)
1.76(R10)
2.11(R12)
1.76(R10)
2.11(R12)
1.76(R10)
2
3
4
Column 1
There are also requirements for air barrier systems
so as to restrict air leakage and vapour condensation.
The requirements are a maximum air leakage rate under
a differential pressure.
10.3 Other Buildings
For most buildings, other than residential occupancies, Part 2
- Clause 2.1.1.11 of the code specifies that they must comply
with the energy efficiency requirements of either:
The alternative approach detailed in Section 9.38 also
covers thermal insulation requirements for walls, floors and
■
New Buildings Except Low rise Residential Buildings"; or
ceilings applicable to the two climate zones and again takes
into account whether the building has electric space heating.
ASHRAE/IES 90.1 - 1989 "Energy Efficient Design of
■
the MNECB 1997.
Refer to Figure 31 for an extract of Table 9.38.3.1.
Both of these are described elsewhere in this report.
In this case the R values for building envelope components
also includes the thermal resistance of building assemblies
through any portion that does not include framing or furring.
This means that the R-value can include the resistance of all
Apart from the residential buildings, other exceptions to
compliance with this part are:
■
farm buildings; and
■
buildings intended primarily for manufacturing, commercial
layers of materials whereas Section 9.25 specifies the thermal
resistance of only the insulation itself. The R-values for Section
or industrial processing.
9.38 are appropriately greater than those of Section 9.25.
Like Section 9.25, there are also thermal resistance
There are also some other requirements contained in the
requirements for glazing and doors with restrictions on
Ontario Building Code 1997 in addition to the ASHRAE/IES
the total area of glazing permitted but in Section 9.28 the
or MNECB requirements. These include:
requirements are more detailed. The area of glazing cannot
■
Section 5.3 - Thermal resistance of assemblies;
■
Section 5.4 - Air leakage; and
■
Section 5.5 - Vapour diffusion.
exceed 20% of the floor area of the storey nor can it exceed
40% of the wall area of the storey. There are also further
requirements in regards to air filtration and air leakage.
The requirements in both Clause 9.25 and 9.38 are totally
prescriptive. However, the thermal insulation requirements
of Clause 9.38 can be reduced (by not more than 20%) and
the area of glazing increased. This is only permitted if it can
be shown that the total heat loss of the building enclosure
would not exceed the heat loss from the same building if it
complied with all the prescriptive requirements. This is similar
to the typical trade-off methods of other Codes. The Ontario
Building Code does not mention a specific calculation method
60
or computer program.
SECTION ELEVEN
SINGAPORE
I N T E R N AT I O N A L
SECTION 11
S U R V E Y
SINGAPORE
The Singapore Building Control Regulations (1 May 1989)
contain what is basically a single approach - prescriptive
code in comparison to the others reviewed for this study.
The Singapore Building Control Regulations are not explained
in detail, instead, this report deals with a few issues that
may be relevant for future energy provisions of the BCA.
Of particular interest are the requirements for ventilated
buildings and the similarity in climate with northern parts
of Australia.
The Singapore Building Control Regulations has some
specific energy conservation requirements in Chapter 29,
Section 50, Division 10. They cover requirements for:
■
roof and wall insulation;
■
air leakage;
■
location of entry doors;
■
zoning for temperature control;
■
sufficient electric power metering;
■
switching off the air-conditioning automatically in
hotel guess rooms when the rooms are unoccupied;
■
data-logging facilities for collecting data for energy
audits; and
■
limits on the thermal transmittance of the roof.
The Singapore Building Control Regulations also reference
a document titled Handbook on Energy Conservation in
Buildings and Building Services.
Non-air-conditioned buildings must have 10% openable
window area. Singapore requirements are for both the health
and the comfort of the occupants. This can be compared
with the BCA Deemed-to-Satisfy provision of 5%, which is
for health reasons.
62
O F
B U I L D I N G
E N E R G Y
C O D E S
SECTION TWELVE
AUSTRALIA
I N T E R N AT I O N A L
SECTION 12
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
AUSTRALIA
12.1 Regulatory Framework
In Australia, building control is the responsibility of the eight
States and Territories. As such, each State and Territory has
its own Building Act and Regulations. These cover the legal
in their Appendices to the BCA. South Australia also have
details of energy efficiency measures in their Appendix to
the BCA but have not yet gazetted the measures into law.
The measures they contained are outlined in this section.
and administrative requirements of building control within that
Some Councils have also introduced energy efficiency
jurisdiction’s respective boundaries. The Building Code of
measures through planning schemes or building control
Australia is referenced by all regulations as the construction
where permitted. There are over 700 Councils in Australia
standard for buildings, or building work.
and this report will not attempt to cover the various
The Australian Building Codes Board (ABCB) was formed in
requirements introduced at local government level.
1994 by an inter-government agreement as the representative
The Queensland Government is also preparing a model
body for all the governments. It has a clear mandate for
housing code that Councils may choose to use. It is expected
nationally consistent building regulations. The ABCB is made
that it initially it will only be relevant to the South East part
up of representatives of the eight States and Territories as
of the State.
well as representatives from industry and the Commonwealth
Government.
In 1996, BCA96 was introduced with national adoption
achieved by July 1997. BCA96 is a performance-based code
Figure 32
BCA Building compliance routes
incorporating Performance Requirements and Deemed-toSatisfy (DTS) Provisions and Verification Methods. It also has
bound into the document State and Territory variations and
additions applicable within that jurisdiction. A variation is a
Objectives
Guidance Levels
Compliance Levels
change to the base requirements of the BCA96 while an
addition is a further requirement to those in the base
provisions.
Functional Statements
The BCA96 has a performance hierarchy encompassing
Objectives, Functional Statements, Performance Requirements
and the prescriptive DTS Provisions. Building work must
Performance Requirements
(qualitative)
comply with the Performance Requirements.
The Objective sets the communities social objective while
Building Solution
the Functional Statement relates this Objective to buildings.
These are provided for guidance.
Deemed-to-Satisfy Solution
Alternative Solution
A building solution can incorporate either a DTS Solution or
an Alternative Solution or a combination of both. Therefore,
Verification Methods
An Alternative Solution can be any solution as long as it
Documentary Evidence
can be shown that it meets the Performance Requirements.
The BCA specifies four Assessment Methods available to
Expert Judgement
demonstrate this compliance. Figure 32 indicates the BCA
compliance paths.
Comparison with the DTS
The overall structure and compliance path of the BCA
allows flexibility outside the prescriptive DTS Provisions.
Currently the ACT and Victorian require energy efficiency
64
measures under building control. The details are contained
COMPLIANCE WITH THE BCA
Assessment Methods
the DTS Provisions are only one method of compliance.
I N T E R N AT I O N A L
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E N E R G Y
C O D E S
12.2 Scope of Energy Efficiency Measures
12.4 Australian Capital Territory
Both the ACT and Victorian requirements apply only to
The ACT requirements are divided into:
the following classification of buildings:
■
houses (Class 1);
■
multi-storey residential units (Class 2);
■
residential occupancies for long term or transit living for
■
■
new buildings; and
■
additions to buildings.
12.4.1 New buildings
a number of unrelated persons such as hotels, motels,
A new building must achieve a ACT House Energy Rating
aged care facilities and boarding houses. (Class 3); and
Scheme (ACTHERS) of four stars. This assessment must
a residential unit attached to a commercial building
(Class 4).
be carried out by an accredited assessor. The ACTHERS
is based on the CSIRO computer program NatHERS.
The South Australia requirements apply only to houses
12.4.2 Additions to buildings
(Class 1 buildings).
For an addition to a building, the addition can comply either
by achieving four stars with the ACTHERS program or by
12.3 Performance Requirements
having the minimum insulation material required in the roof
Performance can be expressed in many ways. In the
and walls as shown in Figure 33.
Australian context, how the building is to perform is described
in qualitative terms in the BCA, whereas in New Zealand for
example, the performance is quantified.
The Objective, Functional Statement and Performance
Figure 33
Requirements of the ACT, South Australian and Victorian
ACT Table F6
requirements are tabulated below and are generally consistent
Table F6 of ACT Appendix
MINIMUM INSULATION MATERIAL
with each other, with the exemption of the South Australia
Roofs
Objective.
ACT & Victoria
South Australia
The Objective of this Part is
The Objective of this Part
to facilitate efficient use of
is to facilitate efficient use
energy in a building.
of energy in a building to
(a)
R3 insulation material in the ceiling space; or
(b)
R2 insulation material in an exposed raked ceiling
Walls
Objective
minimise greenhouse gases.
R1.5 insulation material in the external wall space
The floor must either be of concrete or have an R-value
Functional
A building is to be designed to achieve efficient use of energy
of 1 including carpet.
Statement
for internal heating and cooling.
For the ACT, the R-value is for the added insulation to the
Performance
A building must have adequate level of thermal performance to
roof and wall and not the total R-value of the element.
Requirement
ensure efficient use of energy for internal heating and cooling.
12.4.3 Exemptions
Certain types of construction are exempted from complying.
The above requirements limit energy efficiency measures to
These are specified in Clause ACT F6.2 and include cavity
thermal performance for heating and cooling which is basically
brick walls, earth-walls, ashlar stone or other masonry walls
the building envelope. This does not take into account the
which have a thickness of not less than 180 mm. There has
other energy saving measures seen in overseas Codes and
Standards such as lighting, service water heating and HVAC.
However, the breadth of the requirements permit consideration
of measures such as glazing, eves and fenestrations which
65
been indications from specialists in the energy field that some
of these exemptions may not be consistent with test data
and so should be reviewed.
are not currently included in the ACT, South Australian and
Also exempted are Class 10 structures (garages, sheds etc),
Victorian DTS provisions.
and certain movable homes).
I N T E R N AT I O N A L
S U R V E Y
12.5 South Australia
The South Australia Appendix to the BCA specifies a Minister’s
O F
B U I L D I N G
E N E R G Y
C O D E S
as stated by the Australian Prime Minister. It is understood
that the AGO is proposing a review AS 2627.1.
Specification SA2.1 - Energy Efficiency - Thermal design
In AS 2627.1 there are two methods for determining the
requirements for residential buildings as the DTS Provisions for
required levels of insulation in roofs/ceilings and walls.
the energy efficiency Performance Requirements. At the time
These are by using:
of writing, this Specification has not yet been passed into law.
■
the recommended thermal resistance levels; and
■
a method of calculating thermal resistance.
12.5.1 Ministers Specification South Australia SA2.1
12.5.1.1 Application
The South Australia requirements extend only to residential
Scope
houses (Class 1 buildings) and new building work must
The standard sets out requirements for roofs/ceilings
comply with either:
and walls that bound dwellings that are heated or cooled by
■
a verification method to demonstrate that the house
refrigeration. It does not cover naturally ventilated houses.
achieves an energy rating of at least 3.5 stars using
the NatHERS system or other approved system;
■
the insulation requirements as specified in AS 2627
Thermal insulation of dwellings, Part 1 - Thermal
insulation of roofs/ceilings and walls in dwellings; or
■
Recommended thermal resistance levels
There are two options available under this section of
the standard, namely:
■
insulation; and
the insulation requirements specified in the Ministers
Guideline.
using thermal resistance determined by additional
■
using thermal resistance determined by total construction.
12.5.1.2 Verification method
A building must achieve a building energy rating of 3.5 stars.
Thermal resistance determined by additional insulation
This option not only allows the use of NatHERS but any other
This option is to use R-values for roof/ceiling and wall
approved rating scheme. This can be completed by an
insulation contained in prescriptive tables. The values vary
accredited assessor.
depending on the climate for the particular location and
whether the dwelling is to be heated or cooled. These tables
12.5.1.3 Insulation requirements of AS 2627.1
AS 2627 Part 1 provides guidance in improving the thermal
performance of the envelopes of dwellings and aims to
achieving thermal comfort within the dwellings in a cost
effective manner. It is not yet known if this stringency level
will achieve the objective of the Australian Government and
whether it may be necessary to "go beyond no regrets"
specify the additional insulation required for roofs/ceilings
and walls and does not take into account the added resistivity
of the other elements of the assembly. The tables are
comprehensive in that all cities and most main towns of
all States and Territories are listed.
Figure 34 is an extract of Table 2.1; that for roofs and ceilings.
Figure 34: Extract from Table 2.1 from AS 2627.1
TABLE 2.1 RECOMMENDED ADDlTIONAL THERMAL RESISTANCE (Rl)*
REQUIREMENTS FOR ROOF/CEILING SPACE OVER THE HEATED AND COOLED AREA. LOCALITIES LISTED BY STATE
NEW SOUTH WALES AND ACT
Roof
66
Locality
ADELONG
ALBURY
ALSTONVILLE
ARDLETHAN
ARMIDALE
BADGERYS CREEK
BALRANALD
BANKSTOWN
Heating
7.5
2.5
0
3
3.5
2
2.5
2
Heating and cooling
4
4
2.5
4
4
3
4
3
I N T E R N AT I O N A L
Figure 35
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
Extract from Table 2.2 from AS 2627.1
TABLE 2.2 RECOMMENDED ADDITIONAL THERMAL RESISTANCE REQUIREMENTS (R1)* FOR WALLS†. LOCALITIES LISTED BY STATE
NEW SOUTH WALES AND ACT
Walls
Locality
Type A
ADELONG
ALBURY
ALSTONVILLE
ARDLETHAN
ARMIDALE
BADGERYS CREEK
BALRANALD
BANKSTOWN
Type B
Space Heat
Central Heat
Central Heating
and central cooling
Space Heat
Central Heat
Central Heating
and Central cooling
1.5
1.5
0
1
1.5
1
1
1
2
2
0
2
2
1.5
1.5
1
2
2
0
2
2
1.5
2
1.5
1
1
0
1
1
1
1
1
1.5
1.5
0
1.5
1.5
1
1
1
1.5
1.5
0
1.5
1.5
1
1.5
1
The method is similar to that for walls. Differences are that
Thermal resistance determined by total construction
R-values are provided for two types of wall construction
The second method permits the evaluation of the thermal
(types A and B) and the type of heating system also effects
resistance for the total construction of the assembly.
the R-value. Figure 35 is an extract of Table 2.2. Wall type A
The first method is followed as described above to determine
is for brick veneer or weatherboard and wall type B is for
the additional R-value of the insulation required for both
cavity brick. Again, this table is comprehensive in that it
roofs/ceilings and walls. Using this value and the following
covers all cities and main towns of all States and Territories.
table from the standard, the corresponding total thermal
resistance of the element can be determined. Refer to
Figures 36 and 37.
There is also an informative appendix in the standard that
Figure 36
Extract from AS 2627.1 for roofs/ceilings
shows common forms of construction of roofs/ceilings and
walls and their total thermal resistance.
Added thermal
Total thermal resistance
resistance from Table 2.1
of roofing/ceiling
(m2.K/W)
(m2.K/W)
This method calculates the thermal resistance to be added
1.5
1.7
to the roofs/ceilings and walls of a dwelling that is heated/
2.0
2.1
and or cooled.
2.5
2.4
3.0
2.7
3.5
2.9
■
the severity of the climate;
4.0
3.1
■
the inherent thermal resistance of the roofs/ceilings
Method of calculation thermal resistance
The calculations take into account:
and wall constructions;
Figure 37
Extract from AS 2627.1 for walls
■
the cost of fuel;
■
the efficiency of the heater or cooler; and
■
the cost of installing insulation.
Added thermal
Total thermal resistance of
resistance from Table 2.2
type A wall (see Clause 2.4.2)
(m2.K/W)
(m2.K/W)
1.0
1.3
and roof/ceilings and the ground floor. These vary dependant
1.5
1.7
upon climate zone in which the building is located. There are
2.0
2.0
three climate zones within South Australia. See Figure 38.
12.5.1.4 Insulation requirements
of the Minister’s Guideline
A building must have the minimum overall R-value for walls
67
I N T E R N AT I O N A L
Figure 38
S U R V E Y
O F
Table 1 from Minister’s Guideline SA 2.1
Minimum overall thermal
resistance (R-value)
Construction element
Roof / Ceiling
External wall
Ground floor
B U I L D I N G
E N E R G Y
C O D E S
for practical reasons. Also exempted are windows,
vents and other openings.
12.6 Victoria
Zone A
Zone B
Zone C
2.4
1.7
1.0
2.7
1.7
1.0
2.9
1.7
1.0
The Victorian requirements allow the following two options
for the new building work to demonstrate compliance with
the energy efficiency requirements:
■
floors, walls and roofs construction in accordance with
the DTS insulation provisions; or
These values are derived from AS 2627 Part 1 but are
included in the Minister’s Specification so that the total energy
■
the building achieves a House Energy Rating of at least
efficiency requirements can be contained in one document.
three stars using the Victorian House Energy Rating
The R-values specified in Table 1 of the Ministers Specification
Scheme (FirstRate) software program.
are deemed to be met if the floor, wall or roof is constructed in
accordance with the construction details specified in Table 2
12.6.1 Insulation requirements
(Figure 39).
Within this first option, floors, walls and roofs must achieve
the minimum R-value specified in Table F6.1 (See Figure 40).
12.5.1.5 Exemptions
Within this option, there are two alternatives available that
As with the ACT, certain types of construction are exempted.
The Minister’s Specification explains that they are exempted
effectively permit trading off wall insulation with floor
Figure 39
Table 2 from Minister’s Specification SA 2.1
Metal pitched roof / flat lined ceiling with bulk insulation between ceiling joists
(Section detail S1)
Ground floor
External wall
Roof/ceiling
Metal or tiled pitched roof/flat lined ceiling with bulk insulation between ceiling joists
plus RFL sarking under roof (Section detail S2)
68
construction.
Metal or tiled pitched roof / flat lined ceiling with bulk insulation above the ceiling joists
(Section detail S3)
As above with foil backed insulation installed above timber ceiling joists (Section detail S3)
Metal or tiled pitched roof / flat lined ceiling with bulk insulation between joists
and bulk insulation above joists (Section detail S4)
Metal or tiled pitched roof / flat lined ceiling with loose bulk insulation between
and above joists (Section detail S4)
Metal deck skillion or flat roof / ceiling with exposed timber rafters, cathedral
ceiling or raked ceiling bulk insulation installed between roof battens and RFL vapour barrier
(Section detail S5 and S6)
Masonry veneer or weatherboard, timber frame with bulk insulation between timber studs
and lined internally (Section detail S7 and S8)
Masonry veneer with R 1.0 foam-insulation board fixed over C external face of timber studs,
lined internally (Section detail S9)
Masonry veneer, timber frame with double sided RFL fixed to the external face of timber studs
with concertina RFL stapled between the studs, lined internally (Section detail S10)
Suspended timber floor, enclosed, ventilated perimeter, polished
Suspended timber floor, enclosed, ventilated perimeter, carpet and underlay
Concrete slab on ground, tiles
Concrete slab on ground, carpet and underlay
R-value of
insulation
2.5
3.0
3.5
2.5
3.0
3.5
2.0
2.5
3.0
2.0
2.5
2.0 between
joists plus 1.5
above joists
3.0
R-value of
element
2.4
2.7
2.9
2.7
3.0
3.5
2.5
2.7
2.9
2.8
3.0
3.0
Climatic
Zone
A
A, B
A, B, C
A
A, B
A, B, C
A
A, B
A, B, C
A, B
A, B, C
A, B, C
3.0
A, B, C
3.0
3.5
4.0
1.5
2.5
2.7
2.9
2.7
A, B
A, B
A, B, C
A, B, C
1.0
1.7
A, B, C
N/A
N/A
N/A
N/A
N/A
1.8
1.0
1.5
3.2
3.7
A, B, C
A, B, C
A, B, C
A, B, C
A, B, C
I N T E R N AT I O N A L
Figure 40
S U R V E Y
O F
Table F6.1 of the Victorian Appendix
B U I L D I N G
E N E R G Y
C O D E S
12.6.2 House energy rating
The second option is to use the FirstRate system to ensure
Vic Table F6.1
MINIMUM OVERALL R VALUES
the building achieves a house energy rating of at least three
Element
Option a
Option b
Roof or ceiling
R2.2
R2.2
External wall
R1.3
R1.7
Ground Floor
R1.0
R0.7
stars. This can be completed by a registered assessor or by
the State Department Energy Victoria.
12.6.3 Exemptions
Victoria exempts from complying the same wall constructions
Note: For the purposes of this Table a wall which separates a Class 2 or 3
building or a Class 4 part of a building from a Class 10a building or
from any roof space is regarded as an external wall.
as does the ACT and South Australia, but only if the floor of
the house is concrete, or masonry, on-ground.
12.6.4 Other requirements
Table F6.2 (Figure 41) provides descriptions of element
In Victoria, chimneys and flues from solid fuel-burning
construction that are deemed to meet the R-values of
appliances must be provided with a damper or flap. This is
Table F6.1.
not a requirement in the ACT or South Australia.
Figure 41
Table F6.2 of the Victorian Appendix
Vic Table F6.2
R VALUES FOR COMMON ELEMENTS
Description of element
R value
Roofs or ceilings
Tiled or metal pitched roof, R2.5 bulk insulation between ceiling joists, lined ceiling
R2.4
Tiled or metal pitched roof, fl as sarking and insulation over rafters, R2.0 bulk insulation between ceiling joists, lined ceiling
R2.2
Metal deck roof, rfl as sarking and insulation, 20 mm air gap, R2.0 bulk insulation installed between joists/beams,
rfl as a vapour barrier, ceiling lining on underside of joists/beams
Metal deck roof, R2.0 bulk insulation installed between rafters, rfl as a vapour barrier, ceiling lining on underside of rafters
R2.2
R2.2
Metal deck roof, R2.0 bulk insulation installed between roof battens, rfl as a vapour barrier, ceiling lining on top of exposed rafters
R2.2
Tiled roof, rfl as sarking and insulation,R2.0 bulk insulation installed between counter battens, optional rfl as a vapour barrier, ceiling lining on top of exposed rafters
R2.2
External walls
Brick/masonry veneer with R1.5 bulk insulation between the studs, lined internally
R1.7
Brick/masonry veneer with R1.0 foam board fixed over the face of the studs, lined internally
R1.7
Brick/masonry veneer with double sided rfl fixed to external face of studs, lined internally
R1.3
Weatherboard/fibre cement cladding, R1.5 bulk insulation between studs, lined internally
R1.7
Weatherboard/fibre-cement, double sided perforated rfl dished between studs lined internally
R1.3
Cavity brick with R0.8 foam board in cavity
R1.3
150 mm concrete panel with R1.0 foam board and lined internally
R1.3
Floors
69
Concrete/masonry on ground
R1.5
Timber framed floor, enclosed perimeter
R1.0
Timber framed floor, unenclosed perimeter, 20 mm foam board fixed to the underside of floor joists
R1.0
Timber framed floor unenclosed perimeter, perforated rfl dished between joists
R1.0
Timber framed floor unenclosed perimeter
R0.7
Note: For the purposes of this Table an enclosed perimeter may incorporate sub-floor ventilation at the rate of approximately 7300 mm2/m.
SECTION THIRTEEN
CONCLUSIONS
I N T E R N AT I O N A L
SECTION 13
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
CONCLUSIONS
The codes reviewed contain many similarities, particularly
The ACT and Victorian energy efficiency measures apply to
the North American ones. Key aspects are summarised
Class 1, 2, 3 and 4 buildings while the SA measures will, when
below with comments in italics where they may be relevant
gazetted, only apply to Class 1 buildings. It is questionable
to Australian.
why a multi-storey, fully air-conditioned five star Class 3 hotel
should be treated the same as a house.
All the Codes contain prescriptive provisions and, for
those that have some form of a performance base,
It is not practical to change the fundamental BCA split
those provisions, if followed, achieve compliance with
of Volume 1 (Classes 2-9) and Volume 2 (Class 1 &
1O) for energy efficiency measures alone. Any change
the performance requirements. Appendix E summarises
could be considered with as part of a broader project.
performance requirements where they exist.
Notwithstanding the BCA volume split, there could be
It should be emphasised that this is a survey of current
requirements presented in a simplified form for smaller
practices. It is known that Canada, the USA and other
buildings of other classes then houses although these
countries are moving to a performance based building
need not necessarily be Class 2 and 3 buildings.
code which will mean significant change that could, in
turn; effect their energy efficiency provisions. The Kyoto
Protocol may also have prompted countries to commence
reviewing their requirements.
13.2 Regulatory Approach - General
Most countries specified one or more approaches. Some, like
the USA, have two or three methods and up to five different
procedures within one method. Further, there are tabulated
13.1 Scope and Format
alternatives or trade-offs within a procedure. However, all
All the codes have very similar structures with some adoption
methods and procedures are generally one of the following:
an approach resulting in two sets of requirements and two
sets of documents. The split may be "residential buildings"
■
A performance approach.
■
A prescriptive approaches with usually a multi-tabular
and "other buildings". Some have other small buildings in
format. This is simplistic to use, however inflexible in a
with residences. The framework is usually similar for these
simple form and complex in a flexible form.
two categories with different specific requirements.
■
complying with the prescriptive tables with a proposed
houses), but not often for residential are lighting and, to a
building. The trade-off approach usually trades-off
lesser degree, HVAC. All codes also focus on the building
envelope R or U values but sometimes can allow trade-
envelope and the main engineering systems including, hot
offs to take into account heating and cooling systems as
water systems, principal equipment, piping insulation and
well. This is moderately flexible.
system controls.
■
An energy rating approach that again compares a
In the Canadian, the USA Model, the Ontario, the California,
notional building to the proposed building but this time
the Hawaii and the NZ Codes, houses and other small
on an energy use, consumption or cost basis. This
buildings, particularly hotels and motels, are all treated in a
appears to be very flexible.
similar manner. Other larger buildings are treated in a more
With some codes, there is a range of alternative methods
extensive manner. This requires a clear definition of a small
for achieving compliance for the whole building or for key
building. NZ has completed some research into the number
elements. Those that are performance based offer prescriptive
of small buildings in the country and have found that
and alternative or trade-off options. These trade-offs often
approximately 90% of buildings are under 300
m2
and
three storeys. It would be considered unreasonable to
expect the designer of a corner shop to carry out the same
energy analysis as the designer of a major shopping centre
71
A trade-off approach which compares a notional building
The main aspects that are included for buildings (other than
just because they are both Class 6 buildings.
relate to the building envelope and major systems.
The proposed New Zealand, proposed Canadian and current
United States codes all contain a method of compliance that
involves comparing the proposed building with a similar
standard building that does comply with code requirements.
I N T E R N AT I O N A L
S U R V E Y
The standard and proposed buildings must have similar
features such as building dimensions, location, fuel sources
and type of use. This allows direct comparison of unique
characteristics and trade-offs between energy saving features.
As the energy consumption analysis is a comparison of the
proposed building with a standard building, any assumptions
made in the calculations that may effect the result, will be
incorporated into both buildings and so minimise any impact.
This is particularly important when using computer software.
O F
B U I L D I N G
E N E R G Y
C O D E S
The BCA Housing Provisions is a self-contained document
covering the most common conditions and referencing
Australian Standards for other conditions. This would be
suitable for a national approach provided there can be a
geographic basis to ventilated houses and provided there are
appropriate reference documents to provide more extensive
details. AS 2627, once amended for the AGO stringency level,
would be a suitable basis in its present form for heated and
air-conditioned buildings but not "ventilated" ones because
The Australian building regulatory framework has an
equivalent to all of these options but outside the BCA
itself. The options are to use a prescriptive DTS
solution or a performance based solution assessed
using a verification method or an assessment method
based on comparison with the DTS provisions. In
Australia, the technical detail of alternative solutions
to meet the performance requirements occur outside
the BCA whereas overseas they are within the codes.
The overseas approach seems to leads to a very
complicated code if maximum flexibility is provided.
Some have mandatory requirements, meaning those particular
requirements cannot be traded, while other requirements for
the same system can be traded.
of its limited scope.
13.4 Regulatory Approach - Other Buildings
Canada and the USA reference the ASHRAE standard 90.1,
the UK the Approved Document L and New Zealand the
New Zealand Standards. These are developed as mandatory
documents and prepared in partnership with code writing
bodies.
The ABCB has a Memorandum of Understanding
with Standards Australia and an agreed procedure for
writing BCA referenced standards in Standardisation
Guide 9.1. The CSIRO scoping study also
recommended that relevant standards be developed
Where trading is permitted between systems, then
the BCA performance requirements could group those
systems. Where trading is not to be permitted then
they could have separate performance requirements
so that each is a requirement in its own right.
All national codes have a national geographic basis with
reliance on tables or maps to show values that vary around
the country. These include weather or location specific data,
R-values and for some, fuel type availability.
This approach is consistent with the BCA. Only Hawaii
and Singapore have provisions for ventilated buildings
and being relatively small jurisdictions, do not vary
those requirements. It will be necessary to determine
if a national approach to ventilated buildings is feasible.
The AGO has funded to ABCB to commission a study
on the feasibility of a national approach to houses and
specifically houses kept comfortable by ventilation
cooling.
with Standards Australia using their existing processes.
An early task for the ABCB will be to liase with
Standards Australia on the framework proposed, new
standards needed, what existing standards need to be
revised and what committees need to be made aware
of the proposals.
The North American codes for public and commercial
buildings, such as the ASHRAE and the IECC, have multipleoptional paths and are very complex. They require specialist
energy expertise to use them and to analyse results. This may
be why North America, the UK and New Zealand group small
buildings together and have a simpler approach.
The development of easier to use measures for smaller
buildings was discussed earlier. For larger buildings,
the systems are very complex and probably need to
be complex. Innovation can still be accommodated
through the BCA performance approach or by trading
13.3 Regulatory Approach - Houses
Most overseas codes have a relatively simple national
approach for houses that usually cover the envelope R-value,
the envelope seal, a limit on the envelope window to wall ratio
and the insulation on SWH piping and ductwork.
72
The BCA approach would also be simplified if there were
no trading permitted between the building envelope and
other systems. This was also suggested in the CSIRO
Scoping Study.
within a reference standard.
13.5 Stated Objective Or Philosophy
The Codes studied have various objectives including
conserving fuel, reducing energy consumption, reducing
greenhouse gas emissions and specifically reducing CO2.
The ACT and Victoria focus on energy efficiency while
South Australia focuses on energy but aims to reduce
greenhouse gases.
I N T E R N AT I O N A L
S U R V E Y
The BCA structure starts with a social objective and
it was a recommendation in the CSIRO Scoping Study
that this objective be greenhouse gas reduction. This
is considered appropriate, seeing it is the Australian
Government’s objective and the reason for considering
measures in the BCA. The use of energy efficiency as
a means of achieving the objective can be introduced
in the Functional Statement or the performance
requirements.
O F
B U I L D I N G
E N E R G Y
C O D E S
There are differences in construction costs around
the Australia and these needs to be considered in
determining the DTS provisions. However, the issue
of the cost of fuels is more complex as cost around
the nation appear to be somewhat arbitrarily set.
Most of Australia is already part of national gas
and power grids with the trend continuing. To avoid
complicating the DTS provisions, measures could
be based on gas for heating and electricity for
13.6 Performance Measures
lighting/power - both at an average cost. Individual
special cases, such as where building owners
Other than New Zealand and the UK, the overseas
codes studied are not strictly performance based in the
Australian context. New Zealand state an absolute quantitative
requirement for houses but the requirement for other buildings
is in qualitative terms. The UK is also qualitative.
The ABCB policy of qualitative performance still
enables quantitative criteria (in conjunction with
specific assumptions) to be developed. This is needed
as a basis for developing DTS provisions and could
also provide one possible verification method for
assessing an alternative solution.
negotiate special energy cost rates, could use
the performance approach.
The situation in Tasmania may need to be further
analysed as most, if not all, of its power comes from
hydro-electricity but even this is not greenhouse gas
free because of the embodied energy in the dam’s
construction. It may also be necessary to consider
the fuel source for Tasmania’s energy "topping-up"
rather than its base source. Further, there is a proposal
to extend the national gas grid across the Bass Strait.
The costing model and economic criteria for
13.7 Stringency Measures And Levels
developing the DTS provisions could also be used
Most other countries use energy as the stringency measure
for their primary objective and it is understood that they all
have some form of cost effectiveness as the stringency level
upper limit.
for the Regulatory Impact Statement (RIS). Therefore,
The BCA structure allows for having a social objective
of reducing greenhouse gasses while having a
performance that relates to energy efficiency measures
in buildings as a means of achieving the objective.
Cost effectiveness can also be introduced by limiting
the performance "to the extent reasonable". However,
performance clauses cannot be further developed
until the AGO sets the stringency currency, be it
"cost effectiveness ", "no regrets" or as the Prime
Minister stated, "beyond no regrets ". Likewise, DTS
provisions cannot be developed until the AGO set
the stringency level.
13.8 Consideration Of Fuel
And Construction Costs
73
The Canadian and USA model codes, and the California code,
have factored in allowances for different fuels, their regional
costs and also regional construction costs within their DTS
solutions. The Canadian code in particular recognises the
different greenhouse gas generation potential of different fuels
and their different supply costs across the country. These
differences effect the selection of energy conserving measures
and add to the complexity of the code.
the methodology could be established and criteria
agreed prior to commencement of the code
development phase.
13.9 Use Of Standard Buildings,
Assumptions, Software
Most countries allow for an assessment method whereby a
proposed building is compared with a standard or notional
reference building that generally complies with the prescriptive
provisions while maintaining most of the proposed buildings
characteristics. Both buildings are assumed to be used and
operate in the same manner.
Particular software is approved for use in energy efficiency
analyses in Canada, New Zealand and in the three Australia
jurisdictions. Some countries have a number of software
packages that are acceptable or may be used at the discretion
of the Approval Authority. Those Australian jurisdictions that
already have energy requirements in their appendices of the
BCA reference particular software packages - all different but
developed from a common source. They are NatHERS,
ACTHERS and FirstRate.
In the Australian regulatory environment, the building
certifier has the authority to decide what method of
calculation is acceptable. There is an increasing
number of packages coming onto the market.
Therefore, the ABCB prefers not to reference software
I N T E R N AT I O N A L
S U R V E Y
in the national BCA. Those Administrations that already
have energy requirements in their appendices and
wish to continue referencing a particular software
O F
B U I L D I N G
E N E R G Y
C O D E S
this study, further investigation into how applications
for exemption are administered would be useful.
The UK refer to a CIBCS publication for ventilated buildings.
package, the will need to consider whether to retain
a variation for this purpose or do it by some other
means.
13.10 Exemptions / Limitations
The range of overseas exemption and limitations are extensive
and include very small buildings, energy used for process
equipment, farm buildings, holiday houses, buildings not using
Hawaii has unique provisions for "ventilated" houses and
the Hawaiian climate is similar to parts of Australia. Further
investigation into the effectiveness of their provisions would
also be useful if Australia is to have similar requirements.
For non-air-conditioned buildings, Singapore requires 10%
openable window area (against the BCA provision of 5%) and
also requires the roof to have specific insulating performance.
A significant part of Australia has a climate suitable for
a well designed "ventilated" house. This is more so
with houses than other types of buildings because
occupants are less restricted in their choice of clothing
- a major factor in being comfortable. It is suggested
that such construction be encouraged and
accommodated in the regulatory system.
much energy, buildings with no heating or cooling proposed
or likely, certain building systems (emergency lighting, smoke
control etc), and where considered "inappropriate". Appendix
B summarises the exemptions.
What is considered a "small building" is usually based on
area and varies from country to country, eg under 100 ft2
area (USA), under 10 m2 (Canada), 30 m2 or less (UK),
under 50 m2 (NZ).
13.12 Extent Of Geographic Zones
Exemption can also be based on energy usage ie under
The extent of climatic or geographic zoning usually
depends upon the size of the country or the diversity of its
climate. Canada has 34 zones for residential buildings while
the USA IECC has 38 for commercial buildings and a DegreeDays system for residential buildings. California alone has 16
climate zones. Being smaller, New Zealand has three and the
UK, Hawaii and Singapore have only one each. In Australia,
the ACT and Victoria have one each while South Australia
has three.
3.4 BTU/Hr/ ft2 (USA) or under 10 w/m2 (Canada).
Some small buildings could be excluded by having a
minimum area limit, alternatively, there could be lesser
requirements for smaller buildings. Industrial buildings
should not be automatically exempted as they are not
exempted from other BCA provisions; only the energy
used by process equipment should be excluded from
calculations.
Currently AS 2627.1 has eight different insulation
Certain constructions in the ACT, SA and Victoria are
zones, ranging from RO to R4 in RO.5 increments.
Although this number appears modest compared with
that of some other countries, it may still be possible
to reduce it further and so reduce the range that
manufacturers must produce and stock. This could
be investigated in conjunction with industry.
exempted from complying. These include walls of cavity
brick, double brick and earth construction over 180 mm
thick. Although it is not a referenced code, it should be
noted that AS 2627.1 has requirements for cavity brick walls
in many locations.
Because the basis is unclear, with the imperative to
reduce greenhouse gas emissions and with possible
advances in building practices, the practice of
exempting some wall constructions should be
revisited. This should be done in consultation with
13.13 Envelope - General
All countries used one or more of the following compliance
methods with some countries permitting all three:
■
a prescriptive method;
■
a comparative method; and
■
an energy rating method.
industry.
13.11 How "Ventilated Buildings" Are Handled
Some countries appear to exempt buildings that are not
to be heated or air-conditioned. It is not known how this is
administered. It is also not known what powers building
officials have to require energy efficiency measures on the
basis that they consider it likely that the building will eventually
74
be heated or air-conditioned. Although beyond the scope of
Most countries permit trading between elements of the
envelope when using a comparative or energy rating method
and this includes the building envelope. However, it is usually
limited to some aspects or elements that may be traded while
others may not be traded. Even where trading is permitted
there may be a limit on the extent of that trading.
I N T E R N AT I O N A L
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
For windows, the UK use a window to wall area ratio for
Investigate, in conjunction with industry, the need for
buildings but use a window to floor area ration for housing.
sealing. For simplicity, it may be sufficient in most of
Canada also use a window to floor ratio for houses.
Australia to require the sealing of only large openings
■
The CSIRO scoping study has recommended that,
because a buildings envelope it may need to last the life
of the building, it should not be traded for supposedly
highly efficient active systems. This approach is fully
supported in houses where there is little to trade-off
against. However, for other buildings it should be realised
that a total prohibition on envelope trading may have the
effect of discouraging innovation. For example, some
buildings have active shading devices rather than passive
ones. The practice of permitting some aspects of the
envelope to be traded but not others, or limiting the extent
of trading, should be further considered. A possible option
may be for the envelope of houses not to be traded while
for buildings, the DTS Provisions could be based on no
trading but permit trading under a performance approach.
13.13.1
Thermal performance of elements
For envelope R-values, the Canadian, USA and NZ Standards
such as flues and other comparable sized penetrations
such as exhaust fans, ventilators, skylights or recessed
light fittings.
13.13.3
Other buildings
Most overseas provisions for envelopes in large buildings
are highly complex but are considerably simpler for smaller
commercial and public buildings. The prescriptive approached,
in particular, for larger buildings can be very detailed taking
into account thermal resistance of walls, floors, roof and
windows as well as radiant gains through windows and
skylights. The radiant gains means that shading devices,
fenestration and building orientation become important.
Usually the simplistic approach is based on value of window
area not being exceeded. The more complex approach
(such as in the USA IECC) give a range of options for the
give overall R-values for the assembled building element. The
performance of all envelope elements as the window
UK Code also provide overall values of assembled building
area increases.
elements but show how insulation contributes to that value.
The current Australian Standard AS 2627.1 allows for different
Specialist expertise may be needed to assess compliance,
even with the supposedly prescriptive provisions.
wall insulation for houses using different heating systems.
This may be technically correct but means that the heating
system would also have to be regulated.
DTS technical provisions, similar to those in countries
with comparable climates, could to be developed
through the Standards Australia process. The ABCB
13.13.2
Housing
should have a coordinating role as the standard, or
For the envelope of houses, most overseas codes cover wall,
standards, would be developed for referencing in the
floor and roof insulation, windows and leakage. Some include
BCA. As earlier considered, there may need to be
shading requirements. The requirements for windows range
a simple approach for the smaller buildings.
from a maximum window to wall ratio up to very complicated
calculations.
13.13.4
Currently the ACT and Victoria require a damper or flap in the
All countries have air tightness requirements with most require
chimneys or flues of open wood burning devices to prevent air
some sealing treatment for the building envelope for both
leakage. There is not a corresponding performance requirement.
housing and other buildings. These range from the provision
South Australia does not have such a requirement but an
of dampers in flues, through sealing of service penetrations
informative appendix refers to the need to seal a range of
penetrations that include an unused fireplace.
The overseas codes studied consider windows
Air tightness
to full caulking of all building joints and window sealing
performance. Some include construction precautions and
on site pressure testing performance.
in houses but the current ACT, SA and Victorian
provisions do not. Windows could be considered, at
least to the extent of a maximum window to wall ratio.
Glazing performance (type, resistance, reflectivity etc)
and shading could also be considered either as added
requirements or as alternatives if the wall to window
75
The USA MEC require recessed light fittings to be sealed.
The necessity for vapour, infiltration and exfiltration
sealing in heated and air-conditioned buildings needs
further investigation and consultation. Because of
ratio is exceeded. However, an overriding
Australia’s more moderate climate, it may be sufficient
consideration should be the ease of use of
to limit sealing to the larger openings such as flues,
the Housing Provisions.
fans, penetrations and possibly recessed lights.
I N T E R N AT I O N A L
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
13.14 HVAC System
13.16 Lighting Systems - Other Buildings
Although the scope varies, all countries surveyed have
requirements for HVAC systems in commercial and public
buildings. Canada, the USA, California and Hawaii also have
requirements for HVAC equipment in houses. Most cover
the efficiencies and fuel type of refrigeration and heating
equipment electric motors, pumps and fans. They also cover
isolating and operating controls, acceptable or prohibited
system types and piping and ductwork insulation.
Most countries have requirements for:
Most have some requirements for houses but usually they are
limited to the efficiency of the basic equipment, the provision
of easily accessible on-off controls and the insulation of the
associated ductwork and piping.
California has requirements for occupancy sensing devices
on lighting systems.
The standards used in Canada and the USA for larger
commercial and public buildings are very extensive and
technically complex requiring specialist expertise to use.
■
high efficiency lighting fittings;
■
maximum lighting density;
■
zoning;
■
switching; or
■
automatic controls.
Some codes exempt display lighting, security lighting and
emergency lighting. However the Californian code requires
display lighting to be included.
Efficiencies of light fittings and components could be
Efficiencies of motors and equipment could be
introduced through AMSC, MEPS or product
standards rather than through building control.
introduced through MEPS and product standards
Technical requirements for HVAC systems should
be developed through Standards Australia in
consultation with industry. Again, the ABCB should
have a coordinating role as the standard would be
referenced by the BCA.
switching, zoning and automatic control could be
rather than through building control.
Provisions for other aspects of lighting, such as
included in a BCA reference standard. Again, the
ABCB should have a coordinating role as the
standard would be referenced by the BCA.
It is recommended that display lighting be exempted
Ductwork insulation was identified in the CSIRO
Scoping Study are an item that could be mandated.
The most appropriate place for ductwork insulation
requirements may be in the ductwork standard, AS
4254. Again, the ABCB should have a coordinating
role as this standard is already referenced by the BCA.
Insulation on hot water piping that is part of plumbing
services (as against HVAC services) could be included
in the plumbing code. Insulating the piping associated
with HVAC systems, such as chilled water and
refrigerant, would still need to be in a BCA referenced
energy standard similar to the ASHRAE standard.
as if it were part of a "process" and emergency lighting
be exempted as it is the minimum needed for safety
and, in any case, not a normally operating system.
13.17 Metering And Monitoring Facilities
Most countries require metering to individual residential units
in apartment blocks and to each floor in multi-storey buildings.
Most Codes also requires monitoring or data logging facilities
in commercial and public buildings to assist energy
management and auditing.
Metering could be required for each individual sole-
13.15 Lighting - Housing
No country regulates internal lighting of private residences.
Some regulate external lighting to the extent of requiring
automatic, or timer actuated, switching. Some have
requirements for lighting in common areas of group housing.
76
occupancy residential units and to each floor, or clearly
defined tenancy where more than one per floor, of a
multi-storey building.
13.18 Lifts
The BCA should not have requirements for internal
lighting in houses or inside sole-occupancy units of
apartments because of the difficulty of ongoing
monitoring.
There does not appear to be any energy efficiency
However, automatically time switched external lighting
in the common areas of Class 2 buildings could be
required. The benefit of extending this to houses could
be further considered.
consumption monitoring or an audit report. It is understood
requirements for lifts within overseas building codes (other
than a general motor efficiency requirement) although their
energy consumption may be included in buildings energy
that Hong Kong is one country that is now drafting an energy
standard for lifts but at the time a writing this report, a copy
has not been seen.
I N T E R N AT I O N A L
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
The views of the lift industry could be sought and any
ABEC and CSIRO are also of the view that
requirements deemed appropriate be introduced
maintenance should be required for systems in
through the Lift Code rather than the BCA.
buildings (other than houses) as the theoretical energy
savings may not be realised if equipment is poorly
13.19 SWH Systems
maintained. The BCA also has the means to require
ongoing maintenance if it is considered essential.
Requirements overseas vary with some countries specifying
heater efficiencies, insulation rating, low water flow heads
and prohibiting pilot flames in their codes.
Equipment efficiencies and specifications could be
developed and implemented through the AMSC,
MEPS or product standards. Details of piping
insulation requirements could be located in the
13.22 Financial Criteria
Most codes, that have an energy cost method, provide
details of a suitable financial model. Hawaii also gives life
cycle analysis formula and advice on selecting an appropriate
discount rate.
Plumbing Code that could then be a BCA reference
None of the codes examined have provision for considering
document.
embodied energy.
As previously proposed, an early task should be to
13.20 Other Equipment
develop an agreed costing model and financial criteria
Some countries have requirements for electric motors and
so that it would be available for the code development
the avoidance of continually burning pilot flames on gas
phase as well as later for the RIS.
equipment.
The USA requires swimming pools and spas to have covers
13.23 Australian Variations And Additions
and have other requirements for pumps, heaters and controls.
The ACT, SA and Victorian provisions vary as to:
California does not permit electric resistance heaters while
Hawaii generally requires heaters to be solar or heat pump
■
insulation or the value of the total element insulation;
type but will accept electric resistance heaters under some
circumstances.
Most equipment manufacturing requirements could
be introduced through AMSC, MEPS and product
standards rather than through building control.
However, as there is no installation standard for pools
whether the R-values stated is the value of the added
■
their treatment of flues and chimneys; and
■
their level of zoning.
None have provisions for naturally ventilated buildings although
it is understood that Queensland is developing a model energy
code for houses that will allow for natural ventilation.
and spas (other than safety in pools) the BCA could
require certain control features and possibly prohibit
A nationally consistent approach needs to be developed
the use of electric heaters. An attempt to regulate
that avoids State and Territory variations and addition
covers may not be practical and possibly should
be an issue for voluntary guidelines.
The selection of pumps (other than HVAC ones
previously covered) may also need to be covered
as their efficiencies vary depending upon their duty.
13.21 Maintenance
Hawaii has requirements that include providing access
for maintenance and the provision of manuals.
The BCA, or its referenced standards, can include
requirements for features needed to facilitate
maintenance.
77
APPENDIX A:
LIST OF CONTRIBUTORS
I N T E R N AT I O N A L
APPENDIX A:
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
LIST OF CONTRIBUTORS
Mr Ali G. Ariani, Housing Development and Building Branch, Ministry of Municipal Affairs and Housing Toronto, Ontario, Canada
Mr Lim Tian Beng, Eng. Building And Construction Authority, Singapore
Mr Raymond B. Bizal P.E., Director Strategic Business Initiatives, International Conference of Building Officials, USA
Mr Robert P. Bowen, Director, Codes and Evaluation, Institute for Research in Construction,
National Research Council Canada Ottawa, Ontario
Mr Hamish Handley, Technical Adviser, Building industry Authority, Wellington, New Zealand
Mr Keith Hatfield, Manager Regulation, Building, Electrical and Plumbing Control, Department of Urban Service ACT, Australia
Mr Nigel Isaacs, Manager, Energy and Environment, BRANZ, New Zealand
Captain Nicholas Lee Choon Hock, Licensing & Enforcement Branch, Fire Safety Bureau, Singapore
Mr Eric Makela, Senior Educational Programs Administrator, International Conference of Building Officials, USA
Mr Peter Nassau, Manager, Policy and Research, Building Control Commission, Melbourne, Australia
Mr Michael W. Suttie, Senior Project Manager, Glumac International, San Francisco, CA, USA
Ms Carolyn Wigg, Chief Project Officer Policy and Technical, Planning SA, Adelaide, Australia.
79
APPENDIX B:
LIST OF REFERENCES
I N T E R N AT I O N A L
APPENDIX B:
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
LIST OF REFERENCES
ABCB, Building Code of Australia, Volumes 1 and 2, 1996, Amendment 7:
ACT Appendix.
South Australia Appendix.
Victoria Appendix.
ASHRAE Standard ANSI/ASHRAE/IESNA 90.1 - 1989, Energy Efficient Design of New Buildings
Except Low-Rise Residential Buildings.
The Building Regulations 1991, Approved Document L, L1 Conservation of Fuel and Power,
Department of the Environment and the Welsh Office, 1995 Edition, HMOS.
Building Control Act (chapter 29, Section 50) Building Control Regulations, 1 May 1989. Singapore.
1998 California Energy Code, California Building standards Commission, USA.
Hawaii Model Energy Code, Hawaii USA
International Energy Conservation Code, 1998, International Code Council.
Institute for Research in Construction, Model National Energy Code of Canada for Buildings, 1997,
Canadian Commission on Building and Fire Codes.
Institute for Research in Construction, Model National Energy Code of Canada for Houses, 1997,
Canadian Commission on Building and Fire Codes.
Isaacs, N. 1999, Performance Based Building Energy Efficiency Code in Proceedings of Global
Building Model in the Next Millennium Convention, Melbourne 12-15 April 1999.
Ministry of Municipal Affairs and Housing, Ontario, Canada, 1997 Ontario Building Code.
NZS 4218: 1996 - Energy Efficiency - Housing and small building envelope, Standards New Zealand.
NZS 4305: 1996 - Energy Efficiency - Domestic Type Hot Water Systems, Standards New Zealand.
NZS 4243: 1996 - Energy Efficiency - Large buildings, Standards New Zealand.
Standards Australia, AS 2627.1-1993 Thermal insulation of dwellings, Part 1: Thermal insulation
of roof/ceilings and walls in dwellings.
81
APPENDIX C - ENERGY CODES
A D O P T E D B Y I N D I V I D U A L S TAT E S O F T H E U S A
I N T E R N AT I O N A L
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
APPENDIX C - ENERGY CODES
A D O P T E D B Y I N D I V I D U A L S TAT E S O F T H E U S A
STATE
83
RESIDENTIAL BUILDINGS
COMMERCIAL BUILDINGS
CODE
EQUIVALENT
APPLICABLE
CODE
Alabama
State Developed Code
93 MEC
All buildings
ASHRAE/IES 90.1
Alaska
State Developed Code
BEES, 95 MEC
State funded residential
construction
None
Arizona
None
Arkansas
State Developed Code
92 MEC
California
State Developed Code Title 24
Colorado
State Developed Code
Conneticut
EQUIVALENT
FUTURE DEVELOPMENTS
APPLICABLE
State owned or funded buildings
Reviewing BEES for public comment
ASHRAE/IES 90.1
State owned facilities
Reviewing 98 IECC to determine if a beneficial energy code
All buildings
ASHRAE/IES 90.1
All buildings
Reviewing IECC and IRC
Exceeds 95 MEC
All buildings
State Developed Code
Exceeds ASHRAE/
IES 90.1
All buildings
CA to skip 2000/2001 code changes and adopt
2003/2004 instead
Less than 92 MEC
Approx 70% of jurisdictions
Voluntary State Provisions
ASHRAE/IES 90.1
Voluntary only
Grant provided to increase energy efficiency and promote
MEC and ASHRAE 90.1
95 MEC
All buildings
ASHRAE/IES 90.1
All buildings
DOE has extended training grant
Delaware
93 MEC
All buildings
ASHRAE/IES 90.1
All buildings
District of Columbia
95 MEC with City amendments
All buildings
ASHRAE/IES 90.1
with city amendments
All buildings
Adoption of 99 BOCA National Code & 98 IECC
Florida
State Developed Code FEECBC
Exceeds 95 MEC
All buildings
State Developed Code
All buildings
Given Grant to extend residential code software
Georgia
95 MEC
-
All buildings
ASHRAE/IES 90.1
Hawaii
State Developed Code
Exceeds 95 MEC
Voluntary to low rise residential
ASHRAE/IES 90.1
-
All counties except Maui
(87% adoption Statewide)
Reviewing MEC commercial for adoption.
Idaho
State Developed Code
Less than 92 MEC
All buildings
ASHRAE 90A-80 & 90B 1975
State developed Code - ICBEC
ASHRAE/IES 90.1
State owned buildings.
Voluntary for private commercial
buildings
Given Grant to support implementation of the
ICBEC & 1995 MEC
Illinois
None
State owned buildings and
city owned buildings
Established committee to review adequacy of current codes
ASHRAE/IES 90.1
Exceeds ASHRAE/
IES 90.1
All buildings
I N T E R N AT I O N A L
STATE
RESIDENTIAL BUILDINGS
CODE
84
EQUIVALENT
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
COMMERCIAL BUILDINGS
FUTURE DEVELOPMENTS
APPLICABLE
CODE
EQUIVALENT
APPLICABLE
Less than ASHRAE
/IES 90.1
All buildings
Undergoing energy code process.
Possible adoption of 98 IECC and IRC
Indiana
92 MEC
All buildings
State Developed Code
Iowa
92 MEC
All buildings
ASHRAE/IES 90.1
All buildings
Grant provided to educate the insurance
industry on the benefits of energy code compliance
Kansas
93 MEC
All buildings
ASHRAE/IES 90.1
All buildings
Grant provided to study energy performance of new
commercial and resident buildings
Kentucky
92 MEC
All buildings
ASHRAE 90A-80 & 90B 1975
All buildings
Louisiana
95 MEC
Low rise residential buildings only
ASHRAE/IES 90.1
Maine
State Developed Code
All buildings
ASHRAE/IES 90.1
All buildings
Maryland
95 MEC
All buildings
ASHRAE/IES 90.1
All buildings
Massachusetts
95 MEC
All buildings
ASHRAE/IES 90.1
All buildings
Michigan
ASHRAE 90A-1980
& 90B 1975
All buildings
ASHRAE 90A-80 & 90B 1975
All buildings
Minnesota
State Developed Code
All buildings
State Amended ASHRAE/
IES 90.1
All buildings
Mississippi
ASHRAE 90-1975
All buildings
ASHRAE 90-1975
State owned, public and high
rise buildings only
Missouri
None
ASHRAE/IES 90.1
State owned buildings only
Montana
93 MEC
ASHRAE/IES 90.1
All buildings
Nebraska
1983 MEC
All buildings
1983 MEC
All except State owned buildings
must comply with ASHRAE/IES 90.1
Nevada
1986 MEC
All buildings
1986 MEC
All except State owned buildings
must comply with ASHRAE/IES 90.1
New Hampshire
ASHRAE 90-1975
All buildings
ASHRAE/IES 90.1
All buildings
New Jersey
ASHRAE 90A-1980
& 90B 1975
All buildings
.
ASHRAE/IES 90.1
All buildings
Less than 92 MEC
93 MEC
-
All buildings
Currently reviewing residential code
Currently developing a new commercial code based on
SHRAE 90.1, IECC and state specific elements
Received Grant to conduct 18 month project to evaluate
effectiveness of 99 Code
As of Jan 1 2000 all state owned buildings must
comply with 1998 IECC
Formed committee to review NJ energy code
I N T E R N AT I O N A L
STATE
RESIDENTIAL BUILDINGS
CODE
85
EQUIVALENT
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
COMMERCIAL BUILDINGS
APPLICABLE
CODE
EQUIVALENT
All buildings
ASHRAE 90A-80 & 90B 1975
All buildings
State Developed Code
ASHRAE/IES 90.1
All buildings
ASHRAE/IES 90.1
FUTURE DEVELOPMENTS
APPLICABLE
New Mexico
92 MEC
New York
State Developed Code
Exceeds 92 MEC
North Carolina
State Developed Code
Simplified 95 MEC version
North Dakota
93 MEC
Contingent on local
jurisdiction adoption
ASHRAE/IES 90.1
Contingent on local
jurisdiction adoption
Ohio
95 MEC
All buildings
ASHRAE/IES 90.1
All buildings
Oklahoma
95 MEC
All buildings
ASHRAE/IES 90.1
State owned and leased facilities
Oregon
State Developed Code
Exceeds 95 MEC
All buildings
State Developed Code
Pennsylvania
State Developed Code
ASHRAE 90A1980 & 90B 1975
All buildings
Rhode Island
95 MEC
South Carolina
95 MEC
South Dakota
None
Tennessee
92 MEC
Texas
Reviewing 98 IECC
All buildings
Review for possible adoption of 2000 IECC
All buildings
-
All buildings
Reviewing IECC and ASHRAE/IESNA 90.1R
for possible adoption
ASHRAE 90A-80 & 90B 1975
All buildings
New adoption of 1998 IECC with review for
adoption of 2000 IECC
All buildings
ASHRAE/IES 90.1
All buildings
Received grant to increase energy efficiency and
emissions reduction.
All buildings
ASHRAE/IES 90.1
All buildings
None
-
All buildings
ASHRAE 90A-80 & 90B 1975
All buildings
93 MEC
Low rise state owned
or funded buildings
ASHRAE/IES 90.1
State owned buildings and
supported institutions
Utah
95 MEC
All buildings
ASHRAE/IES 90.1
All buildings
Vermont
State Developed Code
All buildings
State Developed Code
Virginia
95 MEC
All buildings
ASHRAE/IES 90.1
Washington
State Developed Code
All buildings
State Developed Code
95 MEC
95 MEC
Exceeds ASHRAE
/IES 90.1
All buildings (ASHRAE 90.1 for
state funded buildings)
ASHRAE/IES 90.1
Mandatory to 50% of construction
through land use regulations & Acts
Received grant to improve energy efficiency
in housing in Texas
Currently reviewing requirements
All buildings
ASHRAE/IES 90.1
All buildings
Currently reviewing requirements
I N T E R N AT I O N A L
STATE
RESIDENTIAL BUILDINGS
CODE
West Virginia
ASHRAE 90A-1980
& 90B 1975
Wisconsin
State Developed Code
Wyoming
ASHRAE 90A-1980 & 90B-1975
EQUIVALENT
95 MEC
All buildings
Currently reviewing requirements
All buildings
ASHRAE/IES 90.1
All buildings
Currently reviewing requirements for possible
adoption of 2000 IECC
All buildings
ASHRAE 90A-1980/90B-1975
All buildings
86
Building Energy Efficiency Standards
EQUIVALENT
FUTURE DEVELOPMENTS
ASHRAE 90A-1980/90B 1975
Florida Energy Efficiency Code for Building Construction
Idaho Commercial Building Energy Code
C O D E S
All buildings
FEECBC
International Energy Conservation Code
E N E R G Y
CODE
Model Energy Code
IECC
B U I L D I N G
APPLICABLE
BEES
ICBEC
O F
COMMERCIAL BUILDINGS
A B B R E V I AT I O N S :
MEC
S U R V E Y
APPLICABLE
APPENDIX D - ENERGY EFFICIENCY
REQUIREMENTS IN OVERSEAS CODES
I N T E R N AT I O N A L
S U R V E Y
O F
B U I L D I N G
E N E R G Y
C O D E S
APPENDIX D - ENERGY EFFICIENCY REQUIREMENTS
IN OVERSEAS CODES
COUNTRY
United Kingdom
USA
RELEVANT
DOCUMENT
Approved Document L
IECC
CATEGORY OF
BUILDINGS
BUILDINGS
EXEMPTED
Housing
Small extensions <
10m2
Other buildings
Commercial & Industrial
buildings with no
heating. Small
extensions < 10m2
Residential
≤ 3 storeys
Buildings with no
heating or cooling
GENERAL SCOPE
AND PHILOSOPHY
PERFORMANCE
REQUIREMENTS
Requirements for
components separating
heated space from the
external environment.
Housing without heating
still needs to comply
Yes
Holistic approach to all
components that
contribute to energy
consumption
No
PERFORMANCE
APPROACH.
No
No
Commercial
New Zealand
NZBC
Housing and small
buildings
(≤ 300m2)
Buildings that are not
air-conditioned
Large buildings
Only commercial
buildings that are not
air-conditioned and
≤ 300m2
Capacity ≤ 700L
Domestic hot water
systems
Canada
Canada
Ontario
Australia
88
MNECH
Houses
≤ 3 storeys and ≤ 600m2
in floor area
Log cabins
MNECB
Other Buildings
Buildings ≤ 10m2.
Farm buildings.
Ontario Building
Code 1997
Houses and small
buildings
≤ 3 storeys and ≤ 600m2
in floor area
Other buildings
Buildings ≤ 10m2
Residential
Class 5 to 9 buildings.
Not applicable in States
and Territories other
than ACT, South
Australia and Vic.
BCA96
Requirements for
components separating
heated space from the
external environment.
Housing without heating
still needs to comply
Applies to lighting and the
envelope in conditioned
buildings
Yes
No
All domestic hot water
systems regardless of
source
Protection of the
conditioned space from the
external unconditional
environment
No
No
SYSTEMS AND
ELEMENTS INCLUDED
Envelope, space heating
and SHW
R-ratings in table
format
Average U-value
compared to target Uvalue
SAP rating
incorporating energy
costs over energy
sources
Annual energy use
compared to the annual
energy use of a
reference building
Holistic Approach.
HVAC, fabric losses, SWH, internal
heat gains, solar gains, etc
Envelope, space heating,
SHW and lighting
R-ratings in table
format
Rate of heat loss
compared to that of
reference building
Envelope, HVAC, SHW,
electrical power and lighting
R-ratings in table
format orCalculation
of U-values.
Rate of heat loss or
gain compared to that
of reference building
Annual energy
consumption compared
to set target
consumption
Annual energy costs
compared to reference
building
Holistic Approach.
All energy consuming systems
Envelope, HVAC, SHW,
electrical power and
lighting
U-value in table format
U-values compared to
set U-values
No requirements
R-ratings in table
format
Rate of heat loss
compared to that of
reference building
Annual energy use
compared to reference
building
Holistic Approach.
All energy consuming systems
Envelope, space heating,
SHW and lighting
R-ratings in table
format
Rate of heat loss and
solar aperture
compared to that of
reference building
Annual energy use
compared to reference
building
Holistic Approach.
All energy consuming systems
SWH
Set prescriptive
requirements
Envelope, HVAC, SHW,
electrical power and lighting
Requirements in table
format for effective
thermal resistance
(m2˚C/W)
Requirements in table
format for effective
thermal resistance
(m2˚C/W)
Average thermal
resistance compared to
that of reference
building
Average thermal
resistance compared to
that of reference
building
Annual energy
consumption compared
to set target
consumption
Annual energy
consumption compared
to set target
consumption
Envelope, HVAC and lighting
Envelope, air and vapour
barriers
R-ratings in table
format
Rate of heat loss
compared to that of
reference building
None
Envelope
Thermal resistance of
assemblies.
Air and vapour barriers
Requirements in table
format for effective
thermal resistance
(m2˚C/W)
Average thermal
resistance compared to
that of reference
building
Annual energy
consumption compared
to set target
consumption
Envelope, HVAC, SHW and lighting
Envelope, systems using
energy.
R-ratings in table
format or star rating
using NatHERS
Equivalence to Deemedto-Satisfy
NatHERS , ACTHERS
and VicHERS
Envelope
Envelope, HVAC, SHW,
electrical power and lighting
Thermal resistance
between heated and
unheated spaces
No
No
Buildings ≤ 10m2
Farm buildings.
Commercial and
manufacturing buildings
used for industrial
processing
Requirements for some
components separating
heated space from the
external environment.
Housing without heating
still needs to comply
Yes
Yes
ENVELOPE
COMPONENTS
PRESCRIPTIVE METHODS
COMPARATIVE
ENERGY RATING METHOD
METHOD
EVALUATION
ELEMENTS INVOLVED
Holistic Approach.
HVAC, fabric losses, SWH, internal
heat gains, solar gains, etc
Holistic Approach.
All energy consuming systems
Envelope, HVAC, SHW and lighting