Presentation on theme: "CLIMATE CHANGE GOVERNANCE AND COMPLIANCE"— Presentation transcript:
1CLIMATE CHANGE GOVERNANCE AND COMPLIANCE NBS-M017/NBSLM04DCLIMATE CHANGE GOVERNANCE AND COMPLIANCEControl of Energy use in Buildings Building RegulationsRecipient of James Watt Gold MedalN.K. Tovey (杜伟贤) M.A, PhD, CEng, MICE, CEnvН.К.Тови М.А., д-р технических наук111Session2Session3
2Building Regulations Review of Building Regulations in UK Factors affecting energy consumption and carbon emissionsStandard Assessment ProcedureCode for Sustainable HomesEnergy Performance CertificatesIntroduction in Indian Building RegulationsIntroduction to Chinese Building Regulations
3Introduction 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 1976Building Regulations are divided into sections and associated Approved Documents (ADs)Part A: Structural MatersPart B: FirePart F: VentilationPart H: Heat producing appliancesPart L: Energy Conservation and more recently carbon emissionsEach 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 separatelyThen after 2005 subdivided further into ADL1a and ADL1b covering new and existing buildings.
4Changes in the Heating Standards of Houses First introduced as Part L in 1976Basic Statement – largely following what was then common practicee.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 permitted2002: Carbon Index introduced – but was flawed2006: 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.44
5U-Value Specification with different Regulations 1976198519901994200020052010U – Values W m-2 oC-1SAP< 60SAP > 60External Wall1.00.60.450.35Roof0.250.20.16FloorWindowsNot specified3.02.0*3.32.0Windows as % of external walls17%12%-Windows as % of total floor areas15%22.5%25%
6Comparison of energy consumption for a standard detached house at various ages and improvements (Heat losses in W0C-1)DG – double glazingCAV – cavity wall insulationNumerical value indicates thickness of loft insulation
7Effects of built form on energy consumption (Heat loss WoC-1) BungalowsHousesFlats
8Compliance to Building Regulations Compliance to Building Regulations may be achieved by one of several alternative methods.Elemental MethodSpecifies maximum U-value and perhaps maximum glazed area – valid until 2002 Regs- still used in several other countriesTarget U-value – weighted average U-value allowed some flexibility in designSAP Rating (1994 Regs) – economic assessmentCarbon Index (2002 Regs)Target Emission Rate (Current Regs)
9Building Regulation: Compliance Summary Up to and including 2000 RegulationsElemental Method – specifying U-values of all fabric elements – e.g. Windows, floors, walls, roofsTarget U-Value – allowed some flexibility of design.SAP Rating – an economic measure – only permitted for compliance in 1994 Regs.2000/2002 RegulationsCarbon Index Method- a distorted Carbon Measure2005/6 RegulationsDwelling Emission Rating must be better than Target Emission Rating. Latter is a derivative of the Target U-Value Method.2009/10 RegulationsRetains DER and TER but expects a 25% improvement on performance over 2005/6 standards
10Building Regulation: Compliance Target U – Value Method Calculate Target U-Valuea function of areas of floor, roof, walls, windows etci.e. Weighted average U-Value over all fabric componentsModify targetgas & oil boilers: actual SEDBUK efficiencystandard SEDBUK efficiencyelectric & coal heating: divide by 1.15No modification for heat pumps, biomass, biogas, CHPPurpose of modifications is to give more freedom fordesigns using efficient oil or gas boilersModify target if area south facing windows > area north facing windowsCalculate ACTUAL weighted average U-value of all external surfacesWeighted average U-value must be <= Target valueSEDBUK DatabaseGives 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 insulationIf condensing boiler is used – target U value is easier to achieve. What happens if a non-condensing boiler is fitted in the future
11Standard Assessment Procedure Calculate U-valuesCheck U-values are achievedi.e. Check for bridgingCalculategross heat requirements (Heat Loss Rate)hot water requirementsincidental & solar gainseffective gainseffective internal temperaturecorrected degree-day parameternet space heating total energy requirementSelect heating method (pumps, appliance efficiency)Calculate Total Energy RequirementEstimate energy costs of total space heating, hot water & pumpsDeflate energy by Energy Cost Factor (ECF)– e.g. 1994:0.96, 2001:1.05 etcEstimate SAP on scale 0 – 100+ based on ECFIt is the Economic Aspects which cause problems with SAP Rating
12Critique of the Standard Assessment Procedure (SAP) Energy efficiency index – but gives a rating that is monetary based not energy basedAssumes 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 occupancyIncidental gains based on floor area not occupancyProblem: 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 etc2010 Regulations partly address issue with regard to occupancy – e.g.if TFA > 13.9:N = × [1-exp ( × (TFA-13.9)² )] × (TFA-13.9)if TFA ≤ 13.9: N = 1N is the assumed number of occupants, TFA is the total floor area of dwelling.
13Details are shown in Section 2.1.11 of handout 2006 Regulations Dwelling Emission Rate is method of compliance - essentially the 2010 Regs are similar with only minor variations in detailCriterion 1A 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 methodDetails are shown in Section of handout
14Criterion 2 – limits on design flexibility 2006 Regulations Dwelling Emission Rate is method of compliance - essentially the 2010 Regs are similar with only minor variations in detailCriterion 2 – limits on design flexibilityPerformance 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 DocumentCriterion 3 – Limiting effects of solar overheatingRequires that the effects of overheating in summer must be addressed
15Criterion 4 Quality of Construction 2006 Regulations Dwelling Emission Rate is method of compliance - essentially the 2010 Regs are similar with only minor variations in detailCriterion 4 Quality of ConstructionCriterion 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 InformationRequires information on the maintenance and operation of the building to be made available.
16Simplified Description of Standard Assessment Procedure (SAP) Stage 1 Assess overall heating requirements for building (E)ComponentU-ValueAreaHeat Loss Rate(W oC-1)WallsUwallsAwallsUwalls * AwallsWindowsUwindowsAwindowsUwindows * AwindowsFloorUfloorAfloorUfloor * AfloorRoofUroofAroofUroof * AroofAir changeVolumeVentilationachVV * ach * 0.361Total Heat Loss Rate H = Σux*Ax + V* ach * 0.361Annual Energy RequirementE = H * DegreeDays *86400Stage 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
17CALCULATION of SAP RATING While the Standard Assessment Procedure makes sense the final Rating known as the SAP Rating creates problemsThe 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
18Critique of the Standard Assessment Procedure (SAP) Standing charge ignored for electricity, included for gas. Oil doesn’t have a fixed chargeCan lead to some perverse consequencesLower efficiency oil heating can give a higher SAP rating than more efficient gasEnergy Cost Deflator is neededUnnecessary complication that allows for inflationBut does not allow for differential prices changes between fuelsSAP 1995 – possible SAP rating of over 110SAP of 100 readily achievableSAP 2001 – widened scale (over 120) for consistency with existing scaleSAP 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.
19Impact of Changing Methodology on SAP Rating 2005SAPMains gasLPGOilElectricitySolid mineralBiomass110612920162118193126283029413740395046474859566058686570677674778084828583909291931009499These changes are relatively small compared with changes in previous methodology changes – i.e – 2001 and 2001 – 2006.However these demonstrate the problem of using Economic Cost as a Key Factor in determining the SAP Rating
20Climatic Issue with 2010 Calculations Calculations have to take account of Climate Variations of Solar Gain forAssessment of Cooling RequirementsBut NOT Heating (even though heating requirements will vary by up to +/-25% from one part of country to anotherBenefit of Solar Panels does not account for geographic variations in solar radiation even though this information is available for cooling calculations.
21Improvements for 2010 - Environmental Impact Rating (EI) Calculating the TERTER2010 = (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 RegulationsWhereCh are the carbon emissions associated with for space heating and hot water including any used in circulating pumps,Cl is the equivalent associated with lightingFF is a fuel factor – this is NOT the Emission Factor for the FuelEFA 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.
22Improvements for 2010 - Environmental Impact Rating (EI) Carbon Factor (CF) = (CO2 emissions) / (TFA + 45)where TFA is the Total Floor Areaif CF >= 28.3EI rating = 200 – 95 x log10(CF)if CF < 28.3EI rating = 100 – 1.34 x CFwhere the CO2 emissions are calculated according to the Standard Assessment ProcedureThe EI rating is essentially independent of floor areaIt will vary slightly depending on actual plan shapeA house with zero emissions will have the EI at 100An EI > 100 if a house is a net exporter of energy.Primary energy requirements are also calculated in a similar way to CO2 emissions.
23Improvements for 2010 - Environmental Impact Rating (EI) Letter Rating bands are assigned as followsIt applies to both the SAP rating and the Environmental Impact rating (why the SAP Rating??).Rating BandEI RangeLetter Rating> 92A81 to 91B69 to 80C55 to 68D39 to 54E21 to 38F1 to 20G
24How has the performance of a typical house changed over the years? Original ConstructionBrick – brick cavity wallsMetal windowsSolid floor no insulationNo loft insulationBungalow in South West Norwich built in mid 1950s
25Changing Energy Requirements of House First attempt to address overall consumption. SAP introduced.House constructed in mid 1950sPart L first introduced~>50% reductionIn all years dimensions of house remain same – just insulation standards changeAs houses have long replacement times, legacy of former regulations will affect ability to reduce carbon emissions in future2525
26Changing Energy Requirements of House House constructed in mid 1950sAs Existing but with oil boilerExisting house – current standard: gas boilerImprovements 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.
27Changing Carbon Dioxide Emissions As Existing but with oil boilerHouse constructed in mid 1950sExisting house – current standard: gas boilerNotice 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 2005.2727
28Recipient of James Watt Gold Medal Code for Sustainable HomesMove towards Zero Carbon HomesBut what does Zero Carbon Mean?Recipient of James Watt Gold MedalN.K. Tovey (杜伟贤) M.A, PhD, CEng, MICE, CEnvН.К.Тови М.А., д-р технических наукEnergy Science Director CRed ProjectHSBC Director of Low Carbon Innovation2828
29The 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 dwellingsData for 1 household with 2 cars
30The 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 CO2WaterMaterialsSurface water run-offWastePollutionHeath and well beingManagementEcology
32Credits gained for different improvements Dwelling Emission Rate DER (Maximum 15 credits)% Improvement of DER over TER 2005CreditsMandatory Levels≥10%1Level 1≥14%2≥18%3Level 2≥22%4≥25%5Level 3≥31%6≥37%7≥44%8Level 4≥52%9≥60%10≥69%11≥79%12≥89%13≥100%14Level 5True Zero Carbon15Level 6
33Implications of Code on Carbon Dioxide Emissions House constructed in mid 1950s-10%-18%-25%-44%Code 5: Zero Carbon House for Heating/Hot Water and LightingCode 6: Zero Carbon House overallbut in reality is this achievable?
34Responding to the Challenge: Improvements on the SAP 2005 standards as required by the different code levels can be met by:Improved Fabric performanceLower U-valuesTechnical SolutionsSolar ThermalSolar Photo-voltaicHeat PumpsBiomassMicro- CHPLow Energy Lighting (SAP 2005 already specifies 30%)Energy Service Companies may offer a solution for financingIssues of Carbon Trading
35Responding to the Challenge: Technical Solutions What can be achieved throughImproved Fabric / standard appliance PerformanceUsing SAP 2005 standard referenceExplore different combinations of following improvements.ItemSAP referenceImprovement Option 1Improvement Option 2WindowsU-value = 2U-value = 1.4WallsU-value = 0.35U-value = 0.25U-value = 0.1FloorRoofU-value = 0.16Boiler efficiency78%83% default90% SEDBUK
36SEDBUK DataBase (Seasonal Efficiency of Domestic Boilers in UK) WEB PAGE:
37The Future: Code for Sustainable Homes Improvements in Insulation and boiler performanceCode 1Code 2Option H nearly makes code 3SAP 2005 standardWalls: Wm-2oC-1Windows: 2.0 Wm-2oC-1Boiler η %OptionCO2 Emissions (kg)ReductionCreditsASAP Reference2504BBoiler η = 83% (default)23775%CBoiler η = 90% (SEDBUK)222911%1Dη = 90%: Walls: U = 0.25215014%2Eη = 90%: Walls: U = 0.10203419%3Fη = 90%: Windows: U = 1.4211216%GC + D + F2033HC + E + F191923%4
38The Future: Code for Sustainable Buildings All non-dwellings must display a certificate such as shown>10000m2 from 6th April 2008> 2500m2 from 1st July 2008All non-residential buildings > 1000m2 from 1st October 2008.Separate assessments for air-conditioning plant will be phased in from 1st January 2009Elizabeth 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!!!!!!
39Indian Building Code WEBSITE: http://www.hareda.gov.in/ECBC.pdf Also available at UEA atCode was formulated following Energy Conservation Act of 2001According to Saurabh Kumar, Secretary of Ministry of Power (18th April 2007), Code was to be trialled in demonstration areas from July 2007An initial appraisal suggests that code tends to follow the equivalent of an Elemental Approach, but with differences
40Indian Building CodeUnlike 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 formerIs it sensible to have different standards in different climate regimes?
41Indian Building Code Example of U-values for walls Based on Table of ECBC 2006.Note: The U-value in the UK is0.35 W/m2 oC-1Climate ZoneHospitals, Hotels, Call Centers (24-Hour)Other Building Types (Daytime)Maximum U-factor(W/m2 oC-1)Maximum U-factor (W/m2 oC-1)Composite0.352Hot and Dry0.369Warm and HumidModerate0.4310.397Cold
42Chinese Building CodeChina is adopting a similar approach to that suggested for India
43Chinese Building Code Beijing (2003) 0.82 – 1.16 3.5 0.6 – 0.8 Country/DistrictU-Values (W m-2 oC -1)WallsWindowsRoofBeijing (2003)0.82 – 188.8.131.52 – 0.8Beijing (current)0.6Shanghai (current)1.0Germany0.51.50.22Sweden0.172.50.12UK (2005 Regulations)0.352.00.16Canada0.362.860.23 – 0.4Hokk aido, Japan0.422.330.23Zones in USA similar to Beijing0.32 – 0.452.040.19Zones in Russia similar to Beijing0.44 – 0.772.750.33 – 0.57