NBS-M017/NBSLM04D
2013
CLIMATE CHANGE GOVERNANCE AND
COMPLIANCE
Control of Energy use in Buildings
Building Regulations
Recipient of James Watt Gold Medal
N.K. Tovey (杜伟贤) M.A, PhD, CEng, MICE, CEnv
Н.К.Тови М.А., д-р технических наук
1
Session2
Session3
1
11
Building Regulations
• Review of Building Regulations in UK
– Factors affecting energy consumption and carbon
emissions
– Standard Assessment Procedure
• Code for Sustainable Homes
• Energy Performance Certificates
• Introduction in Indian Building Regulations
• Introduction to Chinese Building Regulations
2
Introduction of Building Regulations
• Until 1965 there were no national Building Codes.
• Previously Local Bye Laws prevailed and modes of construction varied
from one part of UK to another.
• First Building Regulations did not include requirements for Energy
Conservation – these came in 1976
• Building Regulations are divided into sections and associated Approved
Documents (ADs)
•
Part A: Structural Maters
•
Part B: Fire
•
Part F: Ventilation
•
Part H: Heat producing appliances
•
Part L: Energy Conservation and more recently carbon emissions
• Each Part has associated Ads e.g. for Part L the Approved Documents
were originally ADL.
• Subsequently (from 2002) divided into ADL1 and ADL2 covering
dwellings and non-dwelling separately
• Then after 2005 subdivided further into ADL1a and ADL1b covering new
and existing buildings.
3
Changes in the Heating Standards of Houses
• First introduced as Part L in 1976
• Basic Statement – largely following what was then common
practice
e.g. cavity walls brick cavity block with no insulation: no insulation in floor, minimal insulation in loft.
• 1994: First attempt to address overall annual energy
consumption, although elemental method of compliance was
still permitted
• 2002: Carbon Index introduced – but was flawed
• 2006: Target Emission Rate and Dwelling Emission Rate
introduced.
• 2010: Came into force Oct 1st 2010 – relatively minor
updates on 2006 Regulations but noticeable reductions in
allowable emissions.
4
U-Value Specification with different Regulations
1976
1985 1990
1994
2000
2005
2010
U – Values W m-2 oC-1
SAP SAP >
< 60
60
External Wall
1.0
0.6
0.45
0.45
0.35
0.45
0.35
0.35
Roof
0.6
0.35
0.25
0.2
0.16
0.25
0.16
0.16
Floor
1.0
0.6
0.45
0.35
0.25
0.45
0.25
0.25
3.0
2.0*
3.3
2.0
2.0
25%
25%
Windows
Not specified
Windows as %
of external
walls
17%
12%
Windows as %
of total floor
areas
-
-
-
15% 22.5% 25% 22.5%
5
Comparison of energy consumption for a standard detached
house at various ages and improvements (Heat losses in W0C-1)
800
700
unimproved
600
25mm
500
50mm
400
100mm
300
100+CAV
200
100+DG
100
100+DG+CAV
150+DG
0
pre- post- 1960s 1976 1985 1990 1994 2000
war war
DG – double glazing
CAV – cavity wall insulation
Numerical value indicates thickness of loft insulation
200+DG+CAV
250+DG+CAV
6
0
Bungalows
centre
mid-storey
top centre
bottom centre
mid-storey end
top end
bottom end
Houses
semi-detached
600
detached
terraced
500
semi-detached
detached
Effects of built form on energy consumption (Heat loss
WoC-1)
2002
1976
Flats
400
300
200
100
7
Compliance to Building Regulations
• Compliance to Building Regulations may be achieved by
one of several alternative methods.
– Elemental Method
• Specifies maximum U-value and perhaps maximum
glazed area – valid until 2002 Regs
- still used in several other countries
– Target U-value – weighted average U-value allowed
some flexibility in design
– SAP Rating (1994 Regs) – economic assessment
– Carbon Index (2002 Regs)
– Target Emission Rate (Current Regs)
8
Building Regulation: Compliance Summary
Up to and including 2000 Regulations
• Elemental Method – specifying U-values of all fabric
elements – e.g. Windows, floors, walls, roofs
• Target U-Value – allowed some flexibility of design.
• SAP Rating – an economic measure – only permitted for
compliance in 1994 Regs.
2000/2002 Regulations
• Carbon Index Method- a distorted Carbon Measure
2005/6 Regulations
• Dwelling Emission Rating must be better than Target
Emission Rating. Latter is a derivative of the Target UValue Method.
2009/10 Regulations
• Retains DER and TER but expects a 25% improvement on
performance over 2005/6 standards
9
Building Regulation: Compliance Target U – Value Method
• Calculate Target U-Value
– a function of areas of floor, roof, walls, windows etc
– i.e. Weighted average U-Value over all fabric
components
SEDBUK Database
• Modify target
– gas & oil boilers: actual SEDBUK efficiency
standard SEDBUK efficiency
– electric & coal heating: divide by 1.15
– No modification for heat pumps, biomass, biogas, CHP
– Purpose of modifications is to give more freedom for
designs using efficient oil or gas boilers
• Modify target if area south facing windows > area north
facing windows
• Calculate ACTUAL weighted average U-value of all
external surfaces
• Weighted average U-value must be <= Target value
10
Standard Assessment Procedure
• Calculate U-values
• Check U-values are achieved
– i.e. Check for bridging
• Calculate
– gross heat requirements (Heat Loss Rate)
– hot water requirements
– incidental & solar gains
– effective gains
– effective internal temperature
– corrected degree-day parameter
– net space heating total energy requirement
• Select heating method (pumps, appliance efficiency)
• Calculate Total Energy Requirement
• Estimate energy costs of total space heating, hot water & pumps
• Deflate energy by Energy Cost Factor (ECF)– e.g. 1994:0.96, 2001:1.05 etc
• Estimate SAP on scale 0 – 100+ based on ECF
It is the Economic Aspects which cause problems with SAP Rating
11
Critique of the Standard Assessment Procedure (SAP)
• Energy efficiency index – but gives a rating that is monetary based not energy
based
• Assumes a general heating level in house – two zones (one living area one
other). Does not allow for actual temperature settings.
• Hot water requirements based on floor area formula not occupancy
• Incidental gains based on floor area not occupancy
• Problem: Is this a sensible approach?
– If occupancy changes then Rating would change, but it is difficult to
compare actual readings with predicted.
• Alcantar (2008) found problems with methodology for incidental gains etc
• 2010 Regulations partly address issue with regard to occupancy – e.g.
• if TFA > 13.9:
N = 1 + 1.76 × [1-exp (-0.000349 × (TFA-13.9)² )] + 0.0013 × (TFA-13.9)
if TFA ≤ 13.9: N = 1
• N is the assumed number of occupants, TFA is the total floor area of dwelling.
12
2006 Regulations Dwelling Emission Rate is method of compliance
- essentially the 2010 Regs are similar with only minor variations in
detail
• Criterion 1
• A Dwelling Emission Rating (DER) must be
calculated taking due account of the U-values, the
size, the types of heating etc using the Standard
Assessment Procedure (SAP)
• The DER must be shown to be less than the Target
Emission Rating (TER) which is computed with
the same size of building and U-values meeting
those as specified in the Regulations.
Essentially this is a derivative of the target U – value method
• Details are shown in Section 2.1.11 of handout
13
2006 Regulations Dwelling Emission Rate is method of compliance
- essentially the 2010 Regs are similar with only minor variations in
detail
Criterion 2 – limits on design flexibility
• Performance of the building must not be worse than a
given standard.
• gives considerable latitude in design – the old trade-off
problem.
• However criterion attempts to limit this type of trade-off –
see pages 5 and 6 of the Approved Document
Criterion 3 – Limiting effects of solar overheating
• Requires that the effects of overheating in summer must be
addressed
14
2006 Regulations Dwelling Emission Rate is method of compliance
- essentially the 2010 Regs are similar with only minor variations in
detail
Criterion 4 Quality of Construction
• Criterion requires evidence of actual performance – e.g.
changes arising from design modifications, quality of
workmanship.
Some of the requirements involve pressure testing the
building to ensure they have achieved those used in the
design specification.
Criterion 5. Providing Information
• Requires information on the maintenance and operation of
the building to be made available.
15
Simplified Description of Standard Assessment Procedure (SAP)
Stage 1 Assess overall heating requirements for building (E)
Component
U-Value
Area
Heat Loss Rate
(W oC-1)
Walls
Uwalls
Awalls
Uwalls * Awalls
Windows
Uwindows
Awindows Uwindows * Awindows
Floor
Ufloor
Afloor
Ufloor * Afloor
Roof
Uroof
Aroof
Uroof * Aroof
Annual Energy Requirement
E = H * DegreeDays *86400
Air change Volume
Ventilation ach
V
V * ach * 0.361
Total Heat Loss Rate H = Σux*Ax + V* ach * 0.361
Stage 2 Assess hot water/lighting requirements and incidental gains,
efficiency of heating appliance and solar energy etc. Correct annual
consumption to allow for these facts.
Analysis of Stage 1 and 2 generally sound – gives estimates to around 10-15%
Stage 3. Determine the Energy Costs to determine the SAP Rating–
- Serious issues arise with stage
16
CALCULATION of SAP RATING
• While the Standard Assessment Procedure makes sense the
final Rating known as the SAP Rating creates problems
• The SAP rating is related to the total energy cost by the
equations:
• Energy Cost Factor (ECF)
= deflator × total energy cost / (TFA + 45) (10)
• The total energy running cost includes not only heating but
also requirements for hot water, lighting etc as well as
pumps/fans associated with heating. These are proscribed
costs according to a table which are not actual costs.
• The deflator is a factor which varies according to energy costs
and is intended to keep SAP Ratings constant with time
irrespective of changes in fuel prices - this has not been the
case in the past. But this still causes problems with relative
changes between different fuels
17
Critique of the Standard Assessment Procedure (SAP)
• Standing charge ignored for electricity, included for gas. Oil doesn’t
have a fixed charge
• Can lead to some perverse consequences
– Lower efficiency oil heating can give a higher SAP rating than more
efficient gas
• Energy Cost Deflator is needed
– Unnecessary complication that allows for inflation
– But does not allow for differential prices changes between fuels
• SAP 1995 – possible SAP rating of over 110
– SAP of 100 readily achievable
• SAP 2001 – widened scale (over 120) for consistency with existing
scale
• SAP 2005 changed scale to have 100 for zero energy house – means
all previous calculation have to be redone.
– Now possible to get > 100 if a house is carbon negative – i.e. will be
exporting more energy than it consumes.
18
Impact of Changing Methodology on SAP Rating
2005
SAP
1
10
20
30
40
50
60
70
80
90
100
Mains
gas
1
9
19
29
39
48
58
67
76
85
94
LPG
10
20
31
41
50
59
68
76
84
92
99
SAP Rating 2009
Oil
Electricity
1
9
19
29
39
50
60
70
80
90
100
6
16
26
37
46
56
65
74
82
91
99
Solid
mineral
12
21
31
41
50
59
68
77
85
93
100
Biomass
9
18
28
37
47
56
65
74
83
92
100
These changes are relatively small compared with changes in previous
methodology changes – i.e. 1995 – 2001 and 2001 – 2006.
However these demonstrate the problem of using Economic Cost as a Key
Factor in determining the SAP Rating
19
Climatic Issue with 2010 Calculations
Calculations have to take account of
Climate Variations of Solar Gain for
Assessment of Cooling Requirements
But NOT Heating (even though
heating requirements will vary by up to +/25% from one part of country to another
Benefit of Solar Panels does not account
for geographic variations in solar radiation
even though this information is available
for cooling calculations.
20
Improvements for 2010 - Environmental Impact Rating (EI)
Calculating the TER
• TER2010 = (Ch x FF x EFAh + Cl xEFAl) x (1–0.2)* (1 – 0.25)
i.e. a 25% improvement on 2005
This is partly to bring things in align with Code for Sustainable Homes
* The (1 – 0.2) represents a carry over from TER-2005 which indicated a
20% improvement on 2002 Regulations
• Where
Ch are the carbon emissions associated with for space heating
and hot water including any used in circulating pumps,
Cl is the equivalent associated with lighting
FF is a fuel factor – this is NOT the Emission Factor for the Fuel
EFA is the relevant Emission Factor Adjustment and is a ratio of the
emission factors used in the 2009 calculations divided by the equivalent
ones in the 2005 calculations.
21
Improvements for 2010 - Environmental Impact Rating (EI)
• Carbon Factor (CF) = (CO2 emissions) / (TFA + 45)
where TFA is the Total Floor Area
• if CF >= 28.3
EI rating = 200 – 95 x log10(CF)
• if CF < 28.3
EI rating = 100 – 1.34 x CF
where the CO2 emissions are calculated according to the
Standard Assessment Procedure
•
•
•
•
•
The EI rating is essentially independent of floor area
It will vary slightly depending on actual plan shape
A house with zero emissions will have the EI at 100
An EI > 100 if a house is a net exporter of energy.
Primary energy requirements are also calculated in a
similar way to CO2 emissions.
22
Improvements for 2010 - Environmental Impact Rating (EI)
• Letter Rating bands are assigned as follows
It applies to both the SAP rating and the Environmental
Impact rating (why the SAP Rating??).
Rating Band
EI Range
> 92
Letter Rating
A
81 to 91
69 to 80
55 to 68
39 to 54
B
C
D
E
21 to 38
1 to 20
F
G
23
How has the performance of a typical house changed over
the years?
Original Construction
•
•
•
•
Brick – brick cavity
walls
Metal windows
Solid floor no
insulation
No loft insulation
Bungalow in South West Norwich built in mid 1950s
24
Changing Energy Requirements of House
Annual Energy Consumption
30000
25000
kWh
20000
15000
House constructed
in mid 1950s
First attempt to address overall
consumption. SAP introduced.
Part L first
introduced
~>50% reduction
10000
5000
0
Inter post- 1960s 1976 1985 1990 1994 2002 2006
war war
In all years dimensions of house remain same – just insulation standards change
As houses have long replacement times, legacy of former regulations will affect
ability to reduce carbon emissions in future
25
Changing Energy Requirements of House
Annual Energy Consumption
30000
25000
kWh
20000
15000
House constructed
in mid 1950s
As Existing but
with oil boiler
Existing house –
current standard:
gas boiler
10000
5000
0
Inter post- 1960s 1976 1985 1990 1994 2002 2006 gas
war war
oil SAP
2005
Improvements to existing properties are limited because of in built
structural issues – e.g. No floor insulation in example shown.
House designed to conform the Target Emission Rate (TER) as specified
in Building Regulations 2006 and SAP 2005.
26
Changing Carbon Dioxide Emissions
CO2 emissions (kg)
9000
8000
7000
6000
5000
Annual CO2 Emissions
House constructed
in mid 1950s
As Existing but
with oil boiler
Existing house –
current standard:
gas boiler
4000
3000
2000
1000
0
Inter post- 1960s 1976 1985 1990 1994 2002 2006 gas
war war
oil SAP
2005
Notice significant difference between using gas and oil boiler.
House designed to conform the Target Emission Rate (TER) as specified
in Building Regulations 2006 and SAP 2005.
27
Code for Sustainable Homes
Move towards Zero Carbon Homes
But what does Zero Carbon Mean?
Recipient of James Watt Gold Medal
N.K. Tovey (杜伟贤) M.A, PhD, CEng, MICE, CEnv
Н.К.Тови М.А., д-р технических наук
Energy Science Director CRed Project
28
HSBC Director of Low Carbon Innovation
28
The Future: Code for Sustainable Homes
• Introduced over next few years to improve
standards to ultimate “zero carbon house”
• But objectives of a low carbon future may be
jeopardised if attention is not also paid to
sustainable transport associated with new
dwellings
16000
14000
Lighting
12000
Refrigeration
10000
Entertainment
Miscellaneous
8000
Air/Public Travel
6000
Data for 1 household with 2 cars
Washing/Drying
4000
Private Car
2000
Heating
0
1
29
The Code For Sustainable Homes
The Code for Sustainable Homes is a set of sustainable design
principles covering performance in nine key areas.
1. Energy and CO2
9 key areas of performance….
2. Water
3. Materials
4. Surface water run-off
5. Waste
6. Pollution
7. Heath and well being
8. Management
9. Ecology
http://www2.env.uea.ac.uk/cred/harrisongroup/Code_for_Sustainable_Homes.htm
30
Code for Sustainable Homes: Certificates
31
Credits gained for different improvements
Dwelling Emission Rate DER (Maximum 15 credits)
% Improvement of DER over
TER 2005
Credits
Mandatory Levels
≥10%
1
Level 1
≥14%
2
≥18%
3
≥22%
4
≥25%
5
≥31%
6
≥37%
7
≥44%
8
≥52%
9
≥60%
10
≥69%
11
≥79%
12
≥89%
13
≥100%
14
Level 5
True Zero Carbon
15
Level 6
Level 2
Level 3
Level 4
32
Implications of Code on Carbon Dioxide Emissions
8000
CO2 emissions (kg)
7000
House constructed
in mid 1950s
6000
5000
4000
3000
2000
1000
-10%
-18%
-25%
-44%
0
As
current SAP Code 1 Code 2 Code 3 Code 4 Code 5 Code 6
constructed
reference
Code 5: Zero Carbon House for Heating/Hot Water and Lighting
Code 6: Zero Carbon House overall
but in reality is this achievable?
33
Responding to the Challenge:
Improvements on the SAP 2005 standards as required
by the different code levels can be met by:
• Improved Fabric performance
• Lower U-values
• Technical Solutions
•
•
•
•
•
•
Solar Thermal
Solar Photo-voltaic
Heat Pumps
Biomass
Micro- CHP
Low Energy Lighting (SAP 2005 already specifies 30%)
• Energy Service Companies may offer a solution for financing
• Issues of Carbon Trading
34
Responding to the Challenge: Technical Solutions
What can be achieved through
• Improved Fabric / standard appliance Performance
• Using SAP 2005 standard reference
• Explore different combinations of following
improvements.
Improvement
Improvement
Item
SAP
Option 1
Option 2
reference
Windows
Walls
U-value = 2
U-value = 0.35
Floor
Roof
U-value = 0.25
U-value = 0.16
Boiler
efficiency
78%
U-value = 1.4
U-value = 0.25
83% default
U-value = 0.1
90% SEDBUK
35
SEDBUK DataBase
(Seasonal Efficiency of Domestic Boilers in UK)
WEB PAGE: www.sedbuk.com/index.htm
36
The Future: Code for Sustainable Homes
3000
CO2 emissions (kg)
Improvements in Insulation
and boiler performance
Annual CO2 Emissions
2500
Code 1
2000
Code 2
1500
1000
500
0
A
B
C
D
E
Option
A SAP Reference
B Boiler η = 83% (default)
C Boiler η = 90% (SEDBUK)
D η = 90%: Walls: U = 0.25
E η = 90%: Walls: U = 0.10
F η = 90%: Windows: U = 1.4
G C+D+F
H C+E+F
F
G
H
Option H nearly
makes code 3
SAP 2005 standard
Walls:
0.35 Wm-2oC-1
Windows: 2.0 Wm-2oC-1
Boiler η
78%
CO2 Emissions (kg) Reduction
2504
0
2377
5%
2229
11%
2150
14%
2034
19%
2112
16%
2033
19%
1919
23%
Credits
0
0
1
2
3
2
3
4
37
The Future: Code for Sustainable Buildings
All non-dwellings must display a
certificate such as shown
• >10000m2 from 6th April 2008
• > 2500m2 from 1st July 2008
• All non-residential buildings >
1000m2 from 1st October 2008.
• Separate assessments for airconditioning plant will be phased
in from 1st January 2009
Elizabeth Fry Building:
Initially Penalised because it does not
have thermostatically controlled
radiator values .
There are no radiators!!!!!!
Does not get credit for triple/
quadruple glazing – analysis system
cannot cope!!!!!
38
Indian Building Code
• WEBSITE: http://www.hareda.gov.in/ECBC.pdf
• Also available at UEA at
– http://www2.env.uea.ac.uk/gmmc/energy/NBSM14x/Indian_DRAFTECBC27MARCH2006.pdf
Code was formulated following Energy
Conservation Act of 2001
According to Saurabh Kumar, Secretary
of Ministry of Power (18th April 2007),
Code was to be trialled in demonstration
areas from July 2007
An initial appraisal suggests that code
tends to follow the equivalent of an
Elemental Approach, but with
differences
39
Indian Building Code
Unlike UK, elemental
standards vary from region
to region according to
climate.
UK has 18 zones each with
different Degree-Days, but
elemental standards are same
[Technically Scotland could
modify standards in
Scotland]
Two identical houses in UK,
one in South West, the other
in North East Scotland, the
energy consumption for
space heating in latter would
be 47% higher than former
Is it sensible to have different standards in different climate regimes?
40
Indian Building Code
Example of U-values for walls
Based on Table 4.3.2 of ECBC 2006.
Note: The U-value in the UK is
0.35 W/m2 oC-1
Climate Zone
Hospitals, Hotels, Call
Centers (24-Hour)
Maximum U-factor
(W/m2 oC-1)
0.352
Other Building
Types (Daytime)
Maximum U-factor
(W/m2 oC-1)
0.352
Hot and Dry
0.369
0.352
Warm and Humid
0.352
0.352
Moderate
0.431
0.397
Cold
0.369
0.352
Composite
41
Chinese Building Code
China is adopting a similar approach to that suggested for India
42
Chinese Building Code
U-Values (W m-2 oC -1)
Country/District
Beijing (2003)
Walls
Windows
Roof
0.82 – 1.16
3.5
0.6 – 0.8
Beijing (current)
0.6
Shanghai (current)
1.0
Germany
0.5
1.5
0.22
Sweden
0.17
2.5
0.12
UK (2005 Regulations)
0.35
2.0
0.16
Canada
0.36
2.86
0.23 – 0.4
0.42
2.33
0.23
Zones in USA similar to Beijing
0.32 – 0.45
2.04
0.19
Zones in Russia similar to
Beijing
0.44 – 0.77
2.75
0.33 – 0.57
Hokk
aido, Japan
43