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 1: Calculating the target primary energy rate, target emission rate and target fabric energy efficiency rate 1.1 A new dwelling must be built to a minimum standard of total energy performance. This is evaluated by comparing calculations of the performance of the ‘actual dwelling’ against calculations of the performance of a theoretical dwelling called the ‘notional dwelling’. This must be carried out both at the design stage and when work is complete. The notional dwelling is the same size and shape as the actual dwelling and has standardised properties for fabric and services. The full properties of the notional dwelling are set out in the Government’s Standard Assessment Procedure (SAP) for energy rating of dwellings. 1.2 The energy performance of the notional dwelling is described using the following metrics. a. The target primary energy rate, in kWh /m2 per year: this is influenced by the fabric and fuel. PE b. The target emission rate, in kgCO /m2 per year: this is influenced by the fabric and fuel. 2 c. The target fabric energy efficiency rate, in kWh/m2 per year: this is influenced by the fabric only. 1.3 The target primary energy rate, target emission rate and target fabric energy efficiency rate for individual dwellings must be calculated using the Government’s Standard Assessment Procedure, Appendix R. The standardised properties are summarised in Table 1.1. NOTE: For an up-to-date list of approved software, follow the link to SAP 10 at: https://www.gov.uk/guidance/standard-assessment-procedure. 10 Approved Document L Volume 1, 2021 edition Building Regulations 2010 O N L I N E V E R S I O N