Conservation of fuel and power: Approved Document L, Volume 1 — Dwellings

O N L I N E V E R S I O N R24-27C 2.12 When calculating the dwelling primary energy rate and dwelling emission rate for a dwelling connected to a new district heat network, the calculation should include all heat sources to be used up to 31 December 2027. In this way, any planned transition of the heat network to an alternative means of heat generation will be properly accounted for. When there will be a change in heat source up to 31 December 2027, a submission to the building control body should be made to show both of the following. a. That planning permission, if required, has been granted for the change. b. That the heat network will connect to the new source, with confirmation in the form of a signed contract to connect and supply heat. NOTE: When calculating the dwelling primary energy rate and dwelling emission rate for a dwelling connected to an existing district heat network the calculation should not include the effect of any change in heat sources after the dwellings are connected. NOTE: An existing district heat network is defined in Appendix A. A new district heat network should be taken as meaning any other district heat network. NOTE: New dwellings connecting to an existing district heat network should follow the standards in Section 6. Swimming pool basins 2.13 When calculating the dwelling primary energy rate, dwelling emission rate and dwelling fabric energy efficiency rate for a dwelling with a swimming pool, the thermal performance of the pool basin should not be included in the calculation. Instead, the dwelling primary energy rate, dwelling emission rate and dwelling fabric energy efficiency rate should be calculated as if the area covered by the pool were replaced with the equivalent area of floor with the same U-value as the pool surround. Party walls 2.14 When calculating the dwelling primary energy rate, dwelling emission rate and dwelling fabric energy efficiency rate, a party wall U-value for the type of construction adopted should be applied as set out in Table 2.1. Table 2.1 U-values for party walls Party wall construction U-value W/(m2·K) Solid 0.0 Unfilled cavity with no effective edge sealing 0.5 Unfilled cavity with effective sealing around all exposed edges and in alignment with 0.2 insulation layers in abutting elements(1) A fully filled cavity with effective sealing at all exposed edges and in alignment with 0.0 insulation layers in abutting elements(1) NOTE: 1. It is necessary to show that the edge sealing is likely to be robust under normal site conditions. 16 Approved Document L Volume 1, 2021 edition Building Regulations 2010 O N L I N E V E R S I O N