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Part L Structure - Part L 2006 comprises four parts ADL1A ADL1B New dwellings Work in existing dwellings ADL2A ADL2B New buildings other than dwellings Work in existing buildings other than dwellings The four parts shall be used in conjunction with ADF1 Means of ventilation As well as extensive use of second-tier documents Compliance Compliance with ADL no longer by elemental method! Individual building element can not comply with ADL! Only the whole building can comply with ADL in terms of whole building CO2 emissions rate, in kg/(m2·annual). The new ADL gives significant design flexibility – trading off is no longer limited among different building elements. Trading off can be also been taken place between building envelope and building service. It also includes provisions to implement the Energy Performance of Buildings Directive Approach The general approach of complying with ADL would be: Client briefs architects; Architects propose a building, carry out or commission a specialist to carry out whole building CO2 emission rate according to National Calculation Method (NCM), and make sure the proposed building has an CO2 emission rate (BER) less than the target CO2 emission rate (TER), that is BER < TER. Architects specify o o The fraction area and the g factor of the glazing, and The U-values of different cladding zones, and the U-values of major components if necessary. Façade specialist contractors carry out the detailed designs to meet the specification according to second-tier document ‘The thermal assessment of window assemblies, curtain walling and non-traditional building envelopes’ published by CWCT. This approach gives great design flexibility in choosing U-value of components. National calculation method BER and TER are calculated according to the national calculation method (NCM). NCM calculates the annual energy use for a proposed building and comparing it with the energy use of a comparable ‘notional’ building in terms of whole building CO2 emission rate. It takes into account of: Heat loss due to temperature difference between the internal and external environments; Solar heating and shading; Heat lose due to mass migration (air leakage and moisture transfer); Day lighting; Artificial lighting, hot water service, heating and cooling plant, ventilation, etc. Both calculations for proposed and the ‘Notional’ building make use of standard sets of data for different activity areas and call on common databases of construction and service elements. Notional building is the building with the same shape, geometry, and usage as the proposed building that complies with ADL 2002, and with carbon emission rate Cnotional. Target carbon emission rate is calculated for the notional building taking into account of energy improvement factor and the concession of using low and zero carbon emission fuel. TER = Cnotioal x (1 - improvement factor) x (1 - LZC benchmark) ADL2A 2006 gives the energy improvement factor and the LZC benchmark for different types of buildings as following: Servicing strategy Heat and naturally ventilated (include buildings with low levels of heating) Heated and mechanically ventilated Air conditioned Improvement factor LZC benchmark TER 15% 10% 0.765Cnotional 20% 10% 0.72 Cnotional 20% 10% 0.72 Cnotional Calculation software The whole building carbon emission rate shall be calculated using certified software. The software enables you to test the proposed building for compliance with ADL 2006 by any of the two approved routes: Simplified Building Energy Method o iSEMB for non-dwelling buildings o SAP 2005 for dwelling buildings Approved calculation Methodology o IES 'Virtual Environment' software, Version 5.5 o EDSL TAS Version 9.0.9 Schematic diagram of design procedure Worst performance limit ADL 2006 also set out limit for worst performance of building elements. For new dwelling buildings: Element Area-weighted dwelling average Worst individual element Wall 0.35 0.7 Floor 0.25 0.7 Roof 0.25 0.35 Windows, roof windows & rooflights 2.2 3.3 Doors 2.2 3.0 For existing dwelling buildings Element Extensions Renovations Wall 0.30 0.30 Floor 0.22 0.22 Roof 0.16 ceiling 0.20 on pitch 0.16 ceiling 0.20 on pitch 1.8 or BFRC Band D 2.0 or BFRC Band E 2.2 2.2 Wall Area-weighted average (W/m2K) 0.35 Individual element (W/m2K) 0.70 Floor 0.25 0.70 Roof 0.25 0.35 Windows 2.2 3.3 Personnel doors 2.2 3.0 High usage doors 6.0 6.0 Vehicle access doors 1.5 4.0 Windows, roof windows & rooflights Glazed doors For non-dwelling buildings Element Area allowance In order to limit solar over heat, ADL 2006 also sets out the area allowance Building type Windows and doors Rooflights as a % of as % of exposed wall roof area Residential buildings 30 20 Places of assembly, offices and shops 40 20 Industrial and storage buildings 15 20 Mandatory air leakage requirement ADL 2006 requires that air leakage rate shall be no great than 10 m3/h/m2@50Pa. The actual air leakage rate should not be greater than the testing result. Whole building test shall be carried out by accredited testing organisations (currently Taylor Woodrow Engineering and BISRIA). The Building Regulations AD L2A 2006 requires that all buildings with gross floor area greater than 500 m2 should be tested. There is a Statue Law making it an offence for a Building Control Officer to sign off a building without an air leakage test certificate. Buildings with floor area less than 500 m2 should either: Be tested to show that the air leakage rate assumed in the energy modelling has been achieved Modelled with a air leakage rate of 15 m3/(h·m2). (Clearly this is disadvantageous as compensating measures have to be taken elsewhere) Limiting solar gain Temperatures not to exceed 28 oC based on a July day Notional building uses glass with total solar energy transmittance (g-value) of 0.65 Requires consideration of: Area of glass Orientation Glass type Shading devices