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Building Regulations Part L -Conserving Fuel and Power25The four new Approved Documents covering theConservation of fuel and power in buildings came into effecton Thursday 6th April 2006 for use in England and Wales.They further subdivide the distinction betweendwellings and buildings other than dwellingsintroduced in the 1st April 2002 versions into new andexisting building categories and are listed below.L1A New dwellingsL1B Existing dwellingsL2A New buildings other than dwellingsL2B Existing buildings other than dwellingsThere is a common Part L of Schedule 1 whichconsolidates the previous Requirement L1 and L2and covers three distinct requirements.a. limiting heat gains and losses:i. through thermal elements and other parts of thebuilding fabric; andii. from pipes, ducts and vessels used for spaceheating, space cooling and hot water services;b. providing and commissioning energy efficient fixedbuilding services with effective controls;c. providing to the owner sufficient information aboutthe building, the fixed building services and theirmaintenance requirements so that the building canbe operated in such a manner as to use no more fueland power than is reasonable in the circumstances.New Part VA to the RegulationsThere are five other new Regulations to implementthe European Energy Performance of BuildingsDirective (EPBD) Articles 3-6. These are collectivelygrouped under Part VA of the Regulations.17A is about defining the methodology ofcalculating the energy performance of buildings(Article 3 of the EPBD).17B is about setting a minimum energy performancerequirement for buildings based upon a target CO 2emission rate (Article 4 of the EPBD).17C is about new buildings meeting that target CO 2emission rate (Article 5 of the EPBD).17D is about consequential improvements tobuildings and applies to existing buildings with a totaluseful floor area over 1000m 2 , when they undergoextension, initial provision of or an increase in thecapacity of fixed building services (Article 6 of theEPBD). This means that the energy performance ofthe whole building is therefore upgraded.17E gives the interpretation of what a ‘building’ meansand is a building as a whole or parts of it that havebeen designed or altered to be used separately.New Part VI to the Regulations (Miscellaneous)There are three new Regulations to enable checkingthat the building meets the required.CO 2 emission rate. These are collectively groupedunder Part VI of the Regulations.20B is the new regulation concerning air pressuretesting of buildings.20C is about confirming that the fixed buildingservices have been commissioned correctly.20D requires written evidence that the actualbuilding’s CO 2 emission rate has been calculatedcorrectly for the building as constructed and henceis in compliance with Regulation 17C.The four new Approved Documents are more strategicin nature focussing on the key goal of reducing CO 2emissions from buildings. They follow a similarconvention defining key terms and highlighting textagainst a green background as extracts from theBuilding Regulations. As part of the general guidanceeach document looks at the type of work coveredby that Approved Document, technical risk anddemonstrating compliance.Ant WilsonDirector,Faber MaunsellT: 020 8784 5949F: 020 8784 5700E: ant.wilson@fabermaunsell.comW: www.fabermaunsell.com

26 Building Regulations Part L - Conserving Fuel and Power“The four newApprovedDocuments aremore strategic innature focussingon the key goal ofreducing CO 2emissions frombuildings.”New BuildingsThe Approved Documents for new buildings L1Aand L2A are very similar in approach, with sectionson design standards, quality of construction andcommissioning, providing information, model designs,definitions with an appendix containing a compliancecheck list and other documents and standardsreferred to in the text.In showing compliance with the BuildingRegulations the checking comes under fivemain criteria as follows:Criterion 1 Achieving the Target CO 2 Emission Rate(TER) for the building (kg CO 2 per m 2 ).to meet Criterion 3. Software can provide a summaryof the fabric U-values and efficiencies of equipmentfor a check on the limits to design flexibility to meetCriterion 3. Appendix A contains a compliancechecklist and an example of a completed checklistwhich indicates that most of the evidence forcompliance is produced by an Authorised SAPAssessor. Other useful documents, standards andreferences are the final section of the document.The main requirement is for a 20% reduction in theCO 2 emissions rate from dwellings based upon anotional gas boiler heated dwelling of the same sizeand shape. The actual Dwelling Emission Rate (DER)has to be equal or better than the Target EmissionCriterion 2Criterion 3Criterion 4Criterion 5Limits on design flexibility looking atthe performance standards of thebuilding fabric and the fixed buildingservices systems.Limiting solar gains within the buildingsand checking that spaces without airconditioning have appropriate passivecontrol measures to limit the effects ofsolar gains.Quality of the construction of thebuilding and commissioning of the fixedbuilding services to enable checks thatthe performance of the building, asbuilt, is consistent with the calculatedBuilding CO 2 Emission Rate (BER).Providing information about theoperating and maintenance instructionsfor the building so that it can beoperated in such a manner as to use nomore fuel and power than is reasonable.Rate (TER).ADL2A - New buildings other than dwellingsSBEM the Simplified Building Energy Model availablefrom the Building Research Establishment (BRE) canbe freely used for calculating CO 2 emissions forsimple buildings other than dwellings and largedwellings over 450m 2 . More complicated buildingswill need to be evaluated using more accreditedcommercial thermal simulation packages.This software needs to be used by an ApprovedCompetent Person. Guidance is included on thetreatment of shell and core developments andAppendix A provides a compliance checklist whichenables developers and building control bodies toshow compliance with Part L.The main requirement is for a reduction in theBuildings CO 2 Emissions Rate (BER) for the newbuilding. The Target Emission Rate (TER) is basedupon a notional 2002 compliance building with therequirement to achieve between 15% and 20% energyefficiency improvement and a 10% low or zero carbonADL1A - New dwellingsThe calculation methodology approved forpredicting the CO 2 emission rate for dwellingsup to a maximum floor area of 450m 2 is SAP 2005(Standard Assessment Procedure for the EnergyRating of Dwellings). Within this procedure Appendix Pcan be used to check for over heating in the summerbenchmark. This results in air conditioned andmechanically ventilated buildings meeting a 28%overall improvement and heated and naturallyventilated buildings being at least 23.5% better.There is no fixed requirement to employ low or zerocarbon systems as long as the building meets theTarget Emission Rate and the other four criteria.

Building Regulations Part L - Conserving Fuel and Power 27Existing BuildingsThe Approved Documents for existing buildingsL1B and L2B are different due to the fact that therequirement for consequential improvements toimplement Article 6 of the EPBD only requires this forbuildings with a total useful floor area over 1000m 2 .ADL1B - Existing dwellingsADL1B does not have a requirement for consequentialimprovements and focuses on guidance relating tobuilding work on controlled fittings (windows anddoors), controlled services (fixed building servicesequipment) and thermal elements. The main change inthe guidance is for a general improvement in theperformance standards for thermal elements andcontrolled services. More guidance is given on theconstruction of extensions with regard to theelemental standards for the U-values of buildingfabrics and the associated maximum areas ofwindows, roof lights and doors. The new requirementRegulation 4A on thermal elements means thatguidance is given on situations where thermalelements should be upgraded. These are coveredin detail in Appendix A entitled ‘Work to thermalelements’ and also has a very useful Table A1covering two and a half pages on ‘Cost-effectiveU-value targets when undertaking renovation worksto thermal elements’.ADL2B - Existing buildingsother than dwellingsADL2B provides guidance on improvements inthe performance standards for thermal elements,controlled fittings and controlled services.“The main changein the guidanceis for a generalimprovement inthe performancestandards forthermal elementsand controlledservices.”

28 Building Regulations Part L - Conserving Fuel and Power“The latest revisionsto BuildingRegulations Part Lset challenges tothe design teamand all constructionprofessionals.”New Regulation 17D requires consequentialimprovements to energy performance. This applies toan existing building with a total useful floor area over1000m 2 where the proposed building work consists ofor includes:a. an extension;b. the initial provision of any fixed building services; orc. an increase to the installed capacity of any fixedbuilding services.Table 1 in ADL2B lists eight improvements that inordinary circumstances are practically andeconomically feasible. It includes items such asupgrading building services equipment more thanfifteen years old, installing improved control systems,upgrading thermal elements, replacing existingwindows and increasing the on-site low and zerocarbon energy generating systems. It is to be notedthat work that is not technically, functionally oreconomically feasible does not need to be carried outas a consequential improvement. The definition ofeconomically feasible is based upon simplepayback as the marginal additional cost ofincorporating the energy efficiency measure overthe annual energy savings based upon fixed fuelprices quoted in the ADL2B.There are three freely downloadable publications tosupport the Approved Documents available on theDepartment for Communities and LocalGovernment website under the Building Regulationssection. The Domestic Heating Compliance Guide,The Non-Domestic Heating, Cooling and VentilationCompliance Guide and the Low or Zero Carbon EnergySources: Strategic Guide.New ways of workingThe latest revisions to Building Regulations Part L setchallenges to the design team and all constructionprofessionals. Buildings need to meet higher energyefficiency standards in the design, construction andcommissioning processes. Buildings will then havegood instructions for the building operators to actuallydeliver the reduced CO 2 emission that is required.Ant gained a BSc(Hons) in Building (Environmental)Engineering from Bath University and went on to joinOscar Faber (now FaberMaunsell) in 1979. He leadsthe Applied Research group in St. Albans and worksactively within the sustainable development grouppromoting low energy building designs.Ant has worked on a wide range of construction andresearch projects mainly from an energy performanceperspective. He has been working with the ODPM in atraining role on the Buildings Regulations Part L andalso acts as a technical advisor to the Carbon Trust onLow Carbon Building design. Ant is currentlyChairman of the Society of Facade Engineeringand sits on the CWCT technical and standardscommittees. He is a BSRIA and CIBSE Councilmember and on the editorial panel for both BSER&Tand Sustain.Ant has been very involved with thermal modellingand using computer simulation techniques to helpwith building services design. Main areas of interestare sustainable development, environmentalperformance of building facades, renewable energytechnology, dynamic thermal simulation, training,and construction materials.