Energy Efficiency Standards
June2012
LK Reynolds
Sustainability Development Executive
Government gazette – 9 September 2011
Implementation – 9 November 2011
Applicable to new plans & renovations needing
plan approval
CONTENT OF THE PRESENTATION
Introduction
NBR-XA
SAN 10400-XA
Additional Requirements
SANS 204
Green Buildings
FAQ’s
Conclusion
INTRODUCTION
Energy efficiency (EE) in buildings is www (win win win)
South Africa’s energy demand – Demand > Supply
Load shedding
Huge price increases
Buildings are the largest end use of energy and account for
40% of end use of energy & 23% GHG.
Most of this consumption is for heating, cooling, ventilation
and hot water
South Africa signatory to Kyoto protocol
Generally not designed or constructed to maximize energy
efficiency
Feasible saving potentials for EE are very large both in new
and existing buildings
National Building Regulations
Under previous Standards Act – SABS was mandated to
administer National Building Regulations and Building
Standards Act.
NRCS Act of 2008 promulgated
National Building Regulations responsibilities transferred
to National Regulator for Compulsory Specifications
(NRCS)
Both SABS & NRCS report to DTi
Enforcement of NBR is responsibility of Local
Government
NRCS also mandated to ensure proper implementation
& execution of NBR
Aim Of NBR
To ensure safe buildings based on
Acceptable building science practice
Good workmanship
Quality materials
Not intended to be handbook on good building practice
Simple & short way to ensure that buildings will be
designed & built so that persons may live & work in a
healthy, safe environment
Other aspects affecting comfort & convenience are not
controlled by NBR
National Building Regulations and
Building Standards Act, 1977
(Act 103 of 1977)
National Building Regulations
(Functional Regulation)
Rational Design
Deemed-to-Satisfy
SANS 10400
The Application of the
National Building
Regulation
Agrėment
Regulatory Framework
National Building Regulations and Building Standards
Act, 1977 (Act 103 of 1977).
National building regulations are issued in terms of the
above act and is a compilation of various parts (A to X:–
Part A – General Principles and Requirements
Part B – Structural Design
:
Part X – Environmental Sustainability
Part XA – Energy Usage in Buildings
SANS 10400 is a National Standard:
The Application of the National Building Regulations (also
compiled in many parts to correlate to the National Building
Regulations)
National Building
Regulation XA
Rationale behind NBR-XA structure
•
Biggest energy user in residential buildings – Hot water
supply.
– Look to renewable energy or energy efficient sources
– XA2
•
Biggest energy driver is comfort
– Heating, cooling & ventilation
– Building envelope & services
– XA1
Part XA – Energy Usage in New Buildings
XA1 - In order to contribute to the reduction of greenhouse gases, buildings and extensions to
buildings in respect of which plans and specifications are to be drawn and submitted in terms of the Act,
having A1, A2, A3, A4, C1, C2, E1, E2, E3, E4, F1, F2, F3, G1, H1, H2, H3, H4 and H5 occupancies or
building classifications in accordance with Regulation A20, excluding garage and storages areas
contained within such occupancies, shall be designed and constructed so that they:
a)
are capable of using energy efficiently while fulfilling user needs in relation to vertical transport, if any,
thermal comfort, lighting and hot water; or
b)
have a building envelope and services which facilitate the efficient use of energy appropriate to its function
and use, internal environment and geographical location.
Equipment and plant required for conducting the business of the occupant shall be excluded from these
requirements.
XA2 - At least 50 % by volume of the annual average hot water heating requirement shall be provided
by means other than electrical resistance heating including but not limited to solar heating, heat pumps,
heat recovery from other systems or processes and renewable combustible fuel.
XA3 - The requirements of sub-regulation XA1 shall be deemed to be satisfied when such building is
designed and constructed in accordance with the following requirements:
a)
has an orientation of the longest axis, shading, services and building envelope in accordance with SANS
10400-XA; or
b)
is the subject of a rational design by a competent person, which demonstrates that the energy usage of
such building is equivalent to or better than that which would have been achieved by compliance with the
requirements of SANS 10400-XA; or
c)
has a theoretical energy usage performance determined using certified thermal calculation software, less
than or equal to that of a reference building in accordance with SANS 10400-XA.
Occupancies included
Class of Occupancy
Type of Occupancy
A1
Entertainment and public assembly
A2
Theatrical and indoor sport
A3
Place of instruction
A4
Worship
C1
Exhibition Hall
C2
Museum
E1
Place of detention
E2
Hospital
E3
Other institutional (residential)
E4
Medical facilities
F1
Large shop
F2
Small shop
F3
Wholesaler’s store
G1
Office
H1
Hotel
H2
Dormitory
H3
Domestic residence
H4
Detached dwelling house
H5
Hospitality
Occupancies excluded
•
•
•
•
A5 - Outdoor Sport
B1,B2,B3 - Commercial Service Building
D1,D2,D3,D4 - Industrial and Plant rooms
J1,J2,J3,J4 - All garages and storage areas are excluded.
NBR-XA
If mixed occupancy – applies to relevant segment
Where provided, max 50% by volume of hot water can
be from a traditional geyser (paraphrase)
Buildings shall be designed and constructed so that
they
a) are capable of using energy efficiently while fulfilling
user needs in relation to vertical transport, if any,
thermal comfort, lighting and hot water; or
b) have a building envelope and services which facilitate
the efficient use of energy appropriate to its function and
use, internal environment and geographical location.
Equipment and plant required for conducting the business of the occupant is excluded.
Hot Water Supply – XA2
Regulation: A minimum volume fraction of 50% of the
annual average heating requirement for hot water shall
be provided by means other than electric resistance
heating or fossil fuels including, but not limited to
Solar heating
Heat pumps
Geothermal heat
Renewable combustible fuel
Heat recovery from alternative systems and processes
SANS 10400 XA Geyser systems and Pipe
Insulation - requirements
All exposed hot water service pipes shall be clad with insulation with a
minimum R-value in accordance with the table below.
Internal diameter of pipe
Minimum R-value
<80mm
1.0
>80mm
1.5
Determined with a hot surface temperature of 60 °C and an ambient
temperature of 15 °C.
Compliance to NBR-XA – XA3
1 Rational design
 This alternative requires input of a professional “competent” person
 Thermal performance of building needs to be calculated
 Performance should be equal or better than specified in SANS
10400XA
2 “Deemed-to-Satisfy”
 Compliance with requirements in SANS 10400-XA
3 Comparison with a compliant theoretical (reference) building
 Energy usage of building shall be less than or equal to that of a
reference building
 Reference building should be designed to “Deemed to Satisfy”
standards
 This alternative requires input of a professional “competent” person
SANS 10400-XA
Compliance to SANS 10400-XA: Deemedto -satisfy
Option 1: Compliance to SANS 10400XA
 “Recipe” for building elements
 Requirements partially aligned with SANS 204
Option 2: Compliance to Tables
 Thermal performance of building needs to be calculated
 Max Energy Consumption & Max Energy Demand must comply with tables in
SANS 10400-XA
 Thermal performance calculations software accredited by Agrement SA to be
used
 This alternative requires input of a professional “competent” person
Option 3: Comparison with a compliant theoretical (reference) building
 Building design performance – theoretical max energy consumption &
demand shall be less than or equal to that of a reference building
 Building should be designed to “Deemed to Satisfy” standards
 Thermal performance calculations software accredited by Agrement SA to be
used
 This alternative requires input of a professional “competent” person
SANS 10400 – XA (Option 2)
Energy Usage and Building Envelope
Conceptually based on two principles:
Maximum energy demand per unit area(kVA/m2)
Maximum annual energy consumption per unit area
(kWh/m2.a)
Dependent on building classification and
climatic region
SANS 10400 – XA
Energy Usage and Building Envelope
Climatic Zones
Drg.727a
Maximum Energy Demand
1
Classification of
occupancy of
building
2
3
4
5
6
7
8
Maximum energy demanda
VA/m2
Description of building
Climatic zone
1
2
3
4
5
6
A1
Entertainment and public
assembly
85
80
90
80
80
85
A2
Theatrical and indoor sport
85
80
90
80
80
85
A3
Places of instruction
80
75
85
75
75
80
A4
Worship
80
75
85
75
75
80
F1
Large shop
90
85
95
85
85
90
G1
Offices
80
75
85
75
75
80
H1
Hotel
90
85
95
85
85
90
a
The maximum demand shall be based on the sum of 12 consecutive monthly
maximum demand values per area divided by 12/m2 which refers to the nett
floor area.
b
The climatic zones are given in annex B.
Maximum Annual Consumption
1
2
3
4
5
6
7
8
Maximum energy consumption
Classification of
occupancy of
building
kWh/(m2·a)
Description of building
Climatic zonea
1
2
3
4
5
6
A1
Entertainment and
public assembly
420
400
440
390
400
420
A2
Theatrical and indoor
sport
420
400
440
390
400
420
A3
Places of instruction
420
400
440
390
400
420
A4
Worship
120
115
125
110
115
120
F1
Large shop
240
245
260
240
260
255
G1
Offices
200
190
210
185
190
200
H1
Hotel
650
600
585
600
620
630
NOTE 1 The annual consumption per square metre shall be based on the sum of the monthly consumption
of 12 consecutive months.
NOTE 2 Non-electrical consumption, such as fossil fuels, shall be accounted for on a non-renewable
primary energy thermal equivalence basis by converting mega joules to kilowatt hours.
a
The climatic zones are given in annex B.
Building Envelope – Option 1
≈ 25% Roof
Summer
≈ 15% Air
renewal
≈ 30%
Walls
Glazing
Thermal
bridges
≈ 10%
Principle of
insulation
Floor
≈ 10%
Winter
≈ 10% Ground
Improving the building envelope can reduce energy losses and shrink energy
consumption by up to 90%
Building Code References
Orientation
SANS 10400-XA
Shading
SANS 204
Walls
SANS 10400-XA
Fenestration
SANS 10400-XA + SANS 204
Roof Assembly
SANS 10400-XA
Flooring
SANS 10400-XA
Services (excluding hot water)
SANS 204
Energy Usage & Building Envelope (Option 3)
- Orientation
- Shading
Orientation
Compact in plan with most glazing on northern side
Living spaces on northern side
Longer axis of dwelling to be east-west
Roof overhang to shield northern windows in midday summer
sun
Shading
As per SANS 204
Projection of roof overhang - ratios
Total Energy = Energy for cooling + Energy for
heating
Total min = optimal orientation
Total Energy = Energy for cooling + Energy for
heating
Total min = optimal orientation
Shading
Requires a permanent feature which extends horizontally
on both sides of the glazing for the same projection
distance, P (see next slide for figure on shading feature)
or provides the equivalent shading with a reveal or other
shading element (see figure on shading projection) or
have an external shading device which is capable of
restricting at least 80% of summer solar radiation.
For glazing where G exceeds 0,5 m, the value of P (see
figure on shading feature or device) shall be halved.
Shading feature or device
Key
P
horizontal distance,
expressed in metres, from the
glass face to the shadow
casting edge of any shading
projection
H
vertical
distance
from the base of the glazing
element to the same shadow
casting edge used to measure
P
G
vertical
distance
from the head of the glazing
element to the shadow casting
edge of any shading projection
NOTE: An adjustable shading
device that is capable of
completely
covering
the
glazing may be considered to
achieve a P/H value of 2.
Energy Usage and Building Envelope
- Floors
Floors
If in-slab or in-screed heating slab to be insulated with minimum R-value of 1
To calculate the R value you need to know (R value =
Thickness in meters
K value
)
The Thermal conductivity (K value) of the product - expanded polystyrene:
0.036
The product thickness: 40mm
R value =
=
1.111 m²K/W - compliant as a solution
Energy Usage and Building Envelope
- Walls
Non-masonry walls shall achieve a minimum R-value of:
R=2.2 for climatic zones 1&6
R=1.9 for climatic zones 2,3,4&5
Masonry walls shall achieve a minimum R-value of 0.35
Double skin masonry with no cavity, plastered internally; and
either plastered externally or unplastered face masonry
externally
Single leaf masonry with a nominal thickness of at least
140mm plastered internally and rendered externally
Traditional Wall vs. the New Systems
Traditional wall
R = 0.26
Cavity wall, insulation
R = 1.00
Lightweight steel
frame wall
R = 2.50
Cavity wall, dry lining
R = 1.69
ETICS on steel frame
R = 3.76
R-value required for Zone 1 = 2.20
Quoted R-value is subject to thickness of intervention insulation material
ETICS on single
brick wall; R = 2.21
Energy Usage and Building Envelope –
SANS 10400 – XA compliance
Fenestration
Buildings with up to 15% fenestration area to nett
floor area per storey are deemed to satisfy
Buildings with fenestration area to nett floor area
per storey exceeding 15% shall comply with the
requirements for fenestration in SANS 204
Air infiltration shall comply with SANS 613
Fenestration Tables – SANS 204
Energy Usage and Building Envelope
- Roof Assemblies
Roof Assemblies
A roof assembly shall achieve the minimum total R-value
specified in the table hereunder for the direction of heat
flow.
1
2
3
4
5
6
7
Climatic zones
Description
1
2
3
4
5
6
3,7
3,2
2,7
3,7
2,7
3,5
Up
Up
Down and
up
Up
Down
Up
Minimum required total R-value (m²∙K/W)
Direction of heat flow
Calculating the R-value of a roof
The following are taken into consideration when determining the R-value of
a roof construction. The figures can be obtained from SANS 10400-XA.
1- Outdoor Air film (moving air)
7- Direction of
Heat flow
(Affects figures 1,3 & 6)
2- Roofing Material
3-Roof air space
(Ventilated/unventilated)
5-RhinoBoard ceiling
6-Indoor air film (still air)
Example - heat flow up
For a building in Climatic Zones 1 & 4 to meet SANS 10400XA
requirements, the following figures are used and the R-value of insulation is
added.
7- Direction of
Heat flow
1- Outdoor Air film (moving air)
= 0.03
2- Roofing Material
= 0.02
3-Roof air space
(unventilated)
= 0.18
135mm Aerolite Insulation
5-RhinoBoard ceiling
6-Indoor air film (still air)
Total R-value
=3.77 m²K/W
= 3.38
= 0.06
=0.11
Services
Lighting and power
Depending upon occupancy and activity, the
minimum lighting levels shall be determined in
accordance with the requirements of SANS 101141 and SANS 10400-O.
Designers are encouraged to use daylighting in
their designs to reduce the energy used.
The energy demand (power) and energy
consumption for the building shall be determined in
accordance with the requirements given in SANS
204.
Mechanical ventilation and air conditioning
Air conditioning or mechanical ventilation systems (or
both) installed in buildings shall comply with the relevant
national legislation.
The air conditioning or mechanical ventilation system (or
both) shall be designed to best practice.
Designed that in the event of failure of an air
conditioning or mechanical ventilation system (or both),
an alternative means of natural ventilation shall be
provided.
All chilled water, hot water and refrigeration piping,
conditioned air duct work and flexible ducting shall be
insulated to limit heat gain or loss (or both) to not more
than 5% from source to furthest point of delivery on a
system.
Additional Requirements
Additional Requirements for BCO
Competent Person (where necessary) – submit
documentation to local authority as per SANS
10400-A
On Plans
Where provided – location, type & capacity of water
heating installations
Where provided – details of fenestration and
insulation
SANS 204?
Why 2 Energy Efficiency standards?
Does this cause confusion?
Look at International trends….
Europe: Energy Efficiency Targets for
New Residential buildings - 2020
Relative Evolution of building regulations over time (year 2000 = index 100)
120
100
80
60
40
20
DK, FR, DE: evolution of building energy consumption
England/Wales: Code of Sustainable homes
Poland: evolution of U values walls
0
2000
-20
2001
2002
2003
2004
2005
2006
Denmark
Poland
2007
2008
2009
2010
2011
England/Wales
Spain
2012
2013
2014
France
Finland
2015
2016
2017
2018
2019
Germany
Netherlands
2020
How has this been achieved?
Building methodologies have changed in
last 50 years
Driven mainly by speed and energy
constraints
Regulation now driving changes
FACT’s
Fire
Acoustic
Cost Effective
Comfort and Energy Efficiency
Thermal
SANS 204
Energy Efficiency in Buildings
Far more comprehensive than the building regulations
and SANS 10400 – XA
Requirements more stringent (except for roof/ceilings)
In the longer terms regulation to be upgraded and trend
toward SANS 204
It is a voluntary standard
Basic minimum for green star rating
Both standards reduce the use of energy from electricity,
gas, oil, or other fuels used in buildings.
Both standards exclude energy used in the operation of
the building
Green Buildings
Green Buildings
Aspirational Buildings
Green Star Rating Tools
Office, Retail, Multi-unit residential, Public Buildings
Water & Energy Bench-marking (in progress)
Building Interiors & Socio-Economic (starting soon)
Rating for the building/project
“Design” or “As Built” rating
SANS 204 is conditional requirement
More than just energy efficient buildings
Water, waste, transport, indoor environment etc.
FAQ’s
FAQ’s
Does this apply to affordable/RDP/Government
subsidized houses?
Yes – there are no exclusions on residential
buildings
Does this prescribe the installation of Solar
Water Heaters?
No – if not technically feasible, look to other energy
efficient technologies
Not applicable if no hot water supplied
FAQ’s ctd.
Does this call for double glazing?
No – unless building is extreme in design.
How do I know what the R-value is?
Material Manufacturers must supply tested thermal
performance values with thickness of material
required.
FAQ’s ctd.
Are products green rated?
No – projects get the ratings not components of the
project
How do I know how “green” products are?
Look at the requirements in the Green Star Rating
tools & ask manufacturers to supply you with the
test certificate results that demonstrate compliance.
Conclusion
Opportunities
NBR-XA only applies to new buildings and
additions/renovations
Encourage to design to SANS 204
Energy costs escalating annually
Supply of energy is always at risk
Big opportunities in retrofit and re-insulation
Continue to manufacture “standard” thickness’s
Compliant buildings will increase in value
Attraction of Tenants
Tax Incentives