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

O N L I N E V E R S I O N Section 3: Consideration of high-efficiency alternative systems 20 Requirement L1(a): Limiting heat gains and losses 21 Intention 21 Section 4: Limiting heat gains and losses 23 U-values 23 Limiting standards in new dwellings 23 Limiting standards in existing dwellings 24 Continuity of insulation 27 Thermal bridging 28 Airtightness 30 Limiting heat losses and gains from building services 31 Requirements L1(b)(i), (ii) and L2: Fixed building services energy efficiency and controls and on-site generation of electricity 33 Intention 34 Section 5: Minimum building services efficiencies and controls – general guidance 35 New building services 35 Replacement building services in existing dwellings 35 Sizing heating and hot water systems 36 Controls 37 Section 6: System specific guidance 39 Gas-fired heating systems 39 Oil-fired heating systems 42 Electric space heating systems 42 Solid fuel heating systems 43 District heat networks and community heating systems 44 Micro combined heat and power 45 Underfloor heating systems 46 Heat pump heating systems 47 Solar water heating systems 48 Comfort cooling 49 Mechanical ventilation 49 Lighting 50 Building automation and control systems 50 On-site electricity generation and storage 50 vi Approved Document L Volume 1, 2021 edition Building Regulations 2010 O N L I N E V E R S I O N