Part L Volume 2 – Non-Domestic
Approved Document L Volume 2 (2026 edition) sets energy performance requirements for non-domestic buildings under the Future Buildings Standard.
Notional Building
The reference building specification that defines the TER and TPER compliance targets for new non-domestic buildings.
Fabric Standards
Limiting U-values for walls, roofs, floors, windows, and doors – the backstop performance every element must meet.
Heating Requirements
Low-carbon heating mandates, heat pump specifications, flow temperature limits, and the end of fossil fuel heating in new buildings.
Solar PV
The 40% PV rule, heat pump reduction, HRB exemptions, and practical implications for roof design.
Lighting
The 105 lm/W efficacy requirement, lighting controls, display lighting exemptions, and the LENI alternative compliance route.
Ventilation
Specific fan power limits, heat recovery requirements, ductwork airtightness, and mechanical ventilation controls.
Overheating
Solar gain limits for cooled spaces, reference glazing systems, and the link between Part L and Approved Document O.
Approved Document L Volume 2 (2026 edition) provides guidance on meeting the energy efficiency requirements of Part L of the Building Regulations for non-domestic buildings in England. Published on 24 March 2026 as part of the Future Buildings Standard, it replaces the 2021 edition and takes effect from March 2027 (AD L2 2026).
The topics above cover the key technical requirements introduced or tightened under the FBS. Each page draws directly from the approved document and supporting guidance, with inline citations to the relevant sections.