N.K. Tovey ( 杜伟贤 ) M.A, PhD, CEng, MICE, CEnv Н.К.Тови М.А., д-р технических наук

1. N.K. Tovey (杜伟贤) M.A, PhD, CEng, MICE, CEnv Н.К.Тови М.А., д-р технических наук NBS-M017/NBSLM04D 2012 version 2 CLIMATE CHANGE GOVERNANCE AND COMPLIANCE Control of Energy use in Buildings Building Regulations Recipient of James Watt Gold Medal 1 1 1 Session2

2. U-Value Specification with different Regulations

3. Comparison of energy consumption for a standard detached house at various ages and improvements (Heat losses in W0C-1) DG – double glazing CAV – cavity wall insulation Numerical value indicates thickness of loft insulation

4. 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)

5. 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

6. 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

7. 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.

8. 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

9. Impact of Changing Methodology on SAP Rating 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

10. 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.

11. Indian Building Code • WEBSITE: http://www.hareda.gov.in/ECBC.pdf • Also available at UEA at • http://www2.env.uea.ac.uk/gmmc/energy/NBS-M14x/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

12. 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?

13. 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

14. Chinese Building Code China is adopting a similar approach to that suggested for India

15. Chinese Building Code

16. Improvements for 2010 - Environmental Impact Rating (EI) Calculating the TER • TER2010= (Ch x FF x EFAh + ClxEFAl) 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 space heating and hot water including any used in circulating pumps, Clis 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. Note: Error in handout page 21

17. 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

18. 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

19. Changing Energy Requirements of House First attempt to address overall consumption. SAP introduced. House constructed in mid 1950s Part L first introduced ~>50% reduction 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 19

20. Changing Energy Requirements of House As Existing but with oil boiler House constructed in mid 1950s Existing house – current standard: gas boiler 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.

21. Changing Carbon Dioxide Emissions As Existing but with oil boiler House constructed in mid 1950s Existing house – current standard: gas boiler 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. 21

22. 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 Data for 1 household with 2 cars

23. The Code For Sustainable Homes • The Code for Sustainable Homes is a set of sustainable design principles covering performance in nine key areas. 9 key areas of performance…. • Energy and CO2 • Water • Materials • Surface water run-off • Waste • Pollution • Heath and well being • Management • Ecology http://www2.env.uea.ac.uk/cred/harrisongroup/Code_for_Sustainable_Homes.htm

24. Code for Sustainable Homes: Certificates

25. Credits gained for different improvements Dwelling Emission Rate DER (Maximum 15 credits)

26. Implications of Code on Carbon Dioxide Emissions House constructed in mid 1950s -10% -25% -44% -18% Code 5: Zero Carbon House for Heating/Hot Water and Lighting Code 6: Zero Carbon House overall but in reality is this achievable?

27. 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

28. SEDBUK DataBase (Seasonal Efficiency of Domestic Boilers in UK) WEB PAGE: www.sedbuk.com/index.htm

29. 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 air-conditioning plant will be phased in from 1st January 2009 Elizabeth Fry Building: Initially Penalised because it does not have thermostatically controlled radiator values . Does not get credit for triple/ quadruple glazing – analysis system cannot cope!!!!! There are no radiators!!!!!!