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

O N L I N E V E R S I O N L1(b), L2 Table 6.2 Minimum efficiencies for gas-fired heating systems in existing dwellings System type Minimum efficiency Notes Wet heating (e.g. radiators or 92% (as defined in ErP(1)) Or, in exceptional circumstances in underfloor heating) existing dwellings(2), SEDBUK 2009 efficiencies as follows: • 78% for natural gas • 80% for LPG Follow paragraph 6.2 Range cooker with integral central 75% (as defined in SEDBUK 2009) Follow paragraph 6.3 heating boiler Warm air heating BS EN 17082 If a gas-fired circulator is incorporated for domestic hot water, its full and part load efficiency should meet BS EN 15502-2 Follow paragraph 6.4 Independent space heating appliance 63% gross Gross efficiency using the following for primary and secondary space standards as appropriate: 70% net heating • BS EN 1266 • BS 7977-1 • BS EN 613 • BS EN 13278 Follow paragraph 6.5 Inset live fuel-effect combined fire/ 45% for natural gas Gross efficiency using BS 7977-2 back boiler 46% for LPG Follow paragraph 6.6 All types except inset live fuel-effect 63% for natural gas Gross efficiency using BS 7977-2 as combined fire/back boiler appropriate 64% for LPG NOTES: 1. Energy-Related Products Directive. For Standard Assessment Procedure modelling, SEDBUK values should be used. 2. Exceptional circumstances are defined in the ODPM’s Guide to the Condensing Boiler Installation Assessment Procedure for Dwellings. 6.2 If a gas-fired combination boiler is installed in an existing dwelling, at least one of the following energy efficiency measures, appropriate to the system, should be installed. a. Flue gas heat recovery. b. Weather compensation. c. Load compensation. d. Smart thermostat with automation and optimisation. 40 Approved Document L Volume 1, 2021 edition Building Regulations 2010 O N L I N E V E R S I O N