1. ENV-2D02 Energy Conservation
Jane Powell (JC)
Building Regulations

2. What is energy conservation?
Supply and Demand
Supply
More efficient production
CHP
Changing demand
More appropriate use
Fuel switching
Use less
Demand management
Reduce heat loss
Low energy appliances
Behavioural change

3. Why is energy conservation important?
2030 (EU)
Based on present trends
90% imported oil
80% imported gas
Climate change
Limits to fossil fuels
Security
Risks
Threat to our current way of life
Fuel poverty
3 million UK households

4. Observed and simulated change: natural and man-made factors
1.0
0.5
0.0
-0.5
observed
model simulation +
Temperature change ºC +
Source: Hadley Centre

5. UK targets Kyoto targets UK CO2 Targets Renewables
GHG 12.5% below 1990 levels
%; %; %
UK CO2 Targets
Previous target: 20% below 1990 levels by 2010
New target: 60% below 1990 levels by 2050
50% 2010 target can be achieved by energy efficiency measures
Renewables
10% electricity generated by 2010
3.5% 2004

6. Reduce heat loss & behavioural change
Of who?
Occupants
Developers, planners, architects
What method?
Incentives
Subsidies
Economic instruments
Voluntary initiatives
Regulations

7. The Energy Performance of Buildings Directive (EPBD) 2002/91/EC
40% of final energy consumption in the EC is
in the buildings sector.
Improving energy efficiency, carbon emissions
from buildings could be reduced by 22%.
Objectives of the Directive:
To promote the improvement of the energy performance of buildings within the EU through cost effective measures;
To promote the convergence of building standards towards those of Member States which already have ambitious levels.
Measures include:
Methodology for calculating the energy performance of buildings;
Application of performance standards on new and existing buildings;
Certification schemes for all buildings;
Regular inspection and assessment of boilers/heating and cooling installations.
Must be implemented by 4 Jan 2006

8. UK Response Part L Building Regulations (2005)
Comes into force in England and Wales on 6 April 2006 (Scotland & Ireland to follow)
Office of the Deputy Prime Minister (ODPM)
Complies with EU legislation
Move away from energy conservation to carbon emission reduction
UK National Calculation Methodology (NCM) for energy performance of buildings

9. Deficiencies in earlier Building Regulations
Before 1994 if double glazing was used
window area could be doubled
requirements for walls/roof/floor could be relaxed
if overall loss < = standard house (type 1 trade off)
From 1995
Could include incidental gains from appliance use/solar gains
If consumption <= standard house - regulations could be relaxed further
1994 & 2000 regulations
If triple glazing used window area can be increased by 50% (type 2 trade off)
If higher insulations for walls used, greater window area permitted provided <= standard house.
Traditionally framed for minimum compliance rather than actively promoting energy conservation
Less so by 2000 Regs
2005 Regs tightened further

10. Comparison of energy consumption for a standard detached house at various ages and improvements (Heat losses in W0C-1)

11. Effects of built form on energy consumption (Heat loss WoC-1)

12. 1994 Regulations
Single glazing could no longer be used routinely for domestic buildings
Glazed area 22.5% of floor area
50% greater than 1990 regs
50% potential saving lost
Standard Assessment Procedure
(SAP) rating for new buildings
0-100 – higher the better
No target SAP but requirements relaxed if >60
SAP – Regs automatically satisfied
Includes energy running costs in calculation
Trade offs permitted
Does not specify ventilation rates but advise on estimating
Make allowance for solar water heating
Include hot water requirements
Condensing boiler = less requirement for insulation

13. Building Regulations 2000 Current regulations - implemented April 2002
Energy rating method
SAP replaced by Carbon Index method for compliance
SAP ratings still to be calculated and notified to building control bodies
Requirement of heating & hot water changed to encompass overall system performance, not just controls
Boiler seasonal efficiency, inspection & commissioning included
New requirements for efficient lighting systems & provision of information for householders
Standards of fabric insulation improved
Lower (better) standards (loft insulation)
Reductions in U values (technical limits)
Changed methods for calculating U values
Lower U values for windows
Based on sealed double-glazed units with low emissivity panes
Area of glazing increased to 25% floor area
Target U-value method retained but provisions for trade-offs improved.

14. Compliance procedures 2000 Regulations
Three methods to demonstrate compliance with Building Regulations:
Elemental approach
Target U-Value method
Carbon Index
1. Elemental approach – meet specific conditions
Heating must be gas, oil, heat pump, CHP DH, biogas or biomass
U-values < BR2000 standards
Area window, doors, roof lights <=25% floor area
Boiler: SEDBUK efficiency >=78% gas, 80% LPG, 85% oil
[SEDBUK – Seasonal efficiency of domestic boilers in the UK. The average annual efficiency achieved in typical domestic conditions.]

15. 2. Target U-Value method Calculate Target U-Value Modify target
a function of areas of floor, roof, walls, windows etc
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
Modify target if area south facing windows > area north facing windows
Calculate weighted average U-value of all external surfaces
Weighted average U-value must be <= Target value
Gives flexibility in design – if area of windows is lower than 25% U-values of walls can be reduced – does not encourage higher standards of thermal insulation
If condensing boiler is used – target U value is easier to achieve. What happens if a non-condensing boiler is fitted in the future

16. 3. Carbon Index Method Most complex method
Replaces SAP energy rating as a method of compliance
Carbon index appears to be 0-10
Must be >= 8 to comply
Max carbon index 10 – but actually 17.7!
Reality: 8 out of 17.7 or 4.5 out of 10!
SAP procedure is followed
up to point of introducing costs of fuels
actual annual energy consumption is used to calculate the annual carbon dioxide emission
translated into a carbon index

17. Standard Assessment Procedure (2001)
Calculate U-values
Check U-values are achieved
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 – ,

18. Carbon Index Calculations (2000 regulations)
Attempts to assess the true environmental performance of a building
Follow Standard Assessment Procedure to calculate Total Energy Requirement
Calculate CO2 emissions for building
Calculate Carbon Factor (CF)
CF=CO2 (TFA+45) where TFA is total floor space
Carbon Index (CI) CI= log10(CF)
Complication of scale >10
Present regulations (2000) indicate that compliance is 11kg CO2 per m2 – carbon index of 8
If true scale was used Zicer & Elizabeth Fry would out perform the theoretical 10 out of 10 building.
Scale of 0 for high carbon & 10 for low carbon confuses some people who consider the lower the better

19. Total Energy Requirement
SAP
U-values
Total Energy Requirement
Energy costs
Energy Deflator
1-100
1-120 (SAP 2001)
CARBON Index
C02 emissions
Carbon Factor
>=8

20. Carbon emissions for same house designed to different standards

22. 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 – no variation
Hot water requirements based on floor area formula not occupancy
Incidental gains based on floor area not occupancy
Standing charge ignored for electricity, included for gas. Oil doesn’t have a fixed charge (1994 & 2000)
Lower efficiency oil heating can give a higher SAP rating than more efficient gas
Energy Cost Deflator
Unnecessary complication that allows for inflation
1994 Regs – possible SAP rating of over 110
SAP of 100 achievable
2000 Regs – widen scale (over 120) to keep houses at similar value
Better to have max of 100 for zero energy house

23. Effective changes in SAP rating with specific changes (1994 regulations)
SAP changes by:
Change U-values by 10%
2 – 3
Change window area by 10%
1 – 2
Change floor area by 10%
4 – 5
Change heating from mains gas to LPG (little change in energy consumption)
- 15
Change heating from condensing gas to inferior oil
+5-10 !!!!!
Source: Monahan, J (2002) MSc Dissertation UEA;
Turner, C. (2003) BSc Dissertation UEA

24. 2006!!!

25. Draft 2005 Building Regulations
Comes into force 6th April 2006
Will use SAP 2005
Technical changes
Changes in how U values are calculated
Thermal bridging – weighted average to be considered, not just design
Pressure testing of buildings for developments over a specific size
U-values windows – include frames
Information on lighting use
Estimates of overheating in summer included
Shading issues relating to solar gain must be addressed

26. Draft 2005 Building Regulations: Compliance
Greatest change is how compliance is achieved - five criteria:
Dwelling Emission Rate (DER)
Gives considerable latitude in design
Limits on design flexibility
limits trade-offs
Limit effects of solar overheating
South facing windows, ventilation
Quality of construction – evidence of actual performance
Quality of workmanship
Pressure testing of large buildings & developments
Providing information
Maintenance and operation of the building
(Home Information Pack)

27. Dwelling Emission Rate (DER)
Is equal to CO2 emissions per unit floor area for space and water heating and lighting less emissions saved by energy generation
New dwellings & extensions
Non Dwellings & large dwellings >450m2
Building Emission Rate

28. SAP CARBON Index Target Emission Rate U-values
Total Energy Requirement
Energy costs
Energy Deflator
1-100
1-120 (SAP 2001)
CARBON Index
C02 emissions
Carbon Factor
>=8
Target Emission Rate
C02/m2
Dwelling Emission Rate
DER<TER

29. UK National Calculation Methodology (NCM) for energy performance of buildings
Compliance with the 2006 amendments to Part L of the Building Regulations in England and Wales (similar for Scotland and N. Ireland)
Dwellings: NCM new version of the existing Standard Assessment Procedure (SAP)
Non domestic buildings: Simplified Building Energy Model (SBEM)
prototype
user interface called iSBEM.
Purpose: to produce consistent and reliable evaluations of energy use in non-domestic buildings (and some domestic buildings)
for building performance certification purposes (eventually)
(Home information packs - 1 June 2007)

30. SAP 2005 Regulations Basic methods similar to previous regulations
Calculations more complicated
Takes into consideration
window frames
solar gain
energy for lighting
effect of thermal bridges
energy generated by micro CHP, photovoltaics, etc
Problems with monetary values remain
Recalibration of scale
A house with a previous SAP rating will be reduced
SAP 2005 rating is related to the energy cost factor (ECF) by:
If ECF>=3.5, SAP 2005 = *log10(ECF)(1)
If ECF<3.5, SAP 2005 = *ECF (2)
SAP rating scale (1-100) - SAP100 is achieved at zero ECF
Can be >100 if house is net exporter of energy
SAP rating of 100 for something which is zero cost is an improvement on previous versions
But fundamental problem of trying to relate performance to energy prices is a serious limitation particularly due to widely fluctuating energy prices

31. Summary Table of U-values for different Building Regulations

32. English housing tenure by SAP rating, 2001 ODPM (2003)

33. Effects of Building Regulations Part L
2002, 2005 & 2008 amendments should increase efficiency of new build and extensions by 25%
…but will it?

34. What are the barriers to using building regulations to reduce energy use and carbon emissions?

35. UK residential sector accounts for 30% total UK energy demand
1990 – 2003
Total UK energy demand increased 7.3%
Residential energy increased 17.5%
Since 1970
Energy use per household changed little
Overall energy use for residential sector increased by 32%
At household level
Reduction in heat loss – energy saving
Increases in energy demand – lights & appliances

36. Population & households
UK population
current aprox 60 million
– 72 million
Age structure
2003 – 76.2 men, 80.6 women
2031 – 81.0 men, 84.9 women
Total population over 65
m, m, 2060s 17 m
Household size ;
One person households: %, %

37. Effects of household size on energy use Fawcett et al (2000)

38. Construction & demolition
Building regulations are for new houses & extensions
In UK very low levels of construction & demolition
2002/3 167,000 housing starts
1996 – 2004 nearly 160,000 dwellings demolished – 20,000/year
If we continued at this rate the average house will last 1000 years!

39. Future of household energy supply lies in the hands of:
Central government
400 local authorities
25 million households
Appliance and fuel supply industries
Construction building services
Fragmented
Multiple suppliers of specialist products
Huge number of sub contractors
Costs saved by:
reducing capital costs
standard components
standard practices

40. Whole life costs/life-cycle costs
typical costs for owning a building are in the ratio of :
1 for construction costs
5 for maintenance costs
200 for building operating costs
Source: Royal Academy of Engineering

41. Life cycle cost (LCC) Capital cost
+ Present worth of Maintenance and Energy Cost 
- Present worth of Salvage value
Capital cost
initial capital expense for equipment
the system design, engineering, and installation.
Maintenance: operation and maintenance costs/year
Energy cost: yearly fuel cost.
Salvage value: net value in the final year

42. Thank you