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 Section 2: Calculating the dwelling primary energy rate, dwelling emission rate and dwelling fabric energy efficiency rate 2.1 The same approved calculation tool must be used to calculate the target primary energy rate, target emission rate and target fabric energy efficiency rate and the dwelling primary energy rate, dwelling emission rate and dwelling fabric energy efficiency rate. 2.2 The dwelling primary energy rate, dwelling emission rate and dwelling energy efficiency rate must be calculated at both of the following points using the same calculation tool. a. Before work starts, using design values. b. When work is complete, using figures for the building as constructed, and incorporating both of the following. i. Any changes that have been made during construction to the list of specifications. ii. The measured air permeability. 2.3 At both of these points the dwelling primary energy rate, dwelling emission rate and dwelling fabric energy efficiency rate must not exceed the target primary energy rate, target emission rate and target fabric energy efficiency rate, respectively. The specification of the actual dwelling may vary from that of the notional dwelling if the dwelling meets the target primary energy rate, target emission rate, target fabric energy efficiency rate and the guidance in this approved document. Building control notification 2.4 The building control body must be notified, before the work starts, of all the following. a. The target primary energy rate and the dwelling primary energy rate (calculated using design values). b. The target emission rate and the dwelling emission rate (calculated using design values). c. The target fabric energy efficiency rate and the dwelling fabric energy efficiency rate (calculated using design values). d. A list of specifications used in the calculations. Items (a) to (d) above may be reported using the design stage Building Regulations England Part L compliance report (BREL report). For further details of the design stage BREL report, see Appendix B. 2.5 The building control body must be notified, once the work is complete, of all of the following. a. The as-built target primary energy rate and as-built dwelling primary energy rate. b. The as-built target emission rate and as-built dwelling emission rate. c. The as-built target fabric energy efficiency rate and as-built dwelling fabric energy efficiency rate. Building Regulations 2010 Approved Document L Volume 1, 2021 edition 13 O N L I N E V E R S I O N