Conservation of fuel and power: Approved Document L, Volume 2 — Buildings other than dwellings

O N L I N E V E R S I O N L1(a) Requirement L1(a): Limiting heat gains and losses This section deals with the requirements of Part L1(a) of Schedule 1 to the Building Regulations 2010. Requirement Requirement Limits on application Schedule 1 – Part L Conservation of fuel and power L1. Reasonable provision shall be made for the conservation of fuel and power in buildings by— (a) limiting heat gains and losses— (i) t hrough thermal elements and other parts of the building fabric; and (ii) f rom pipes, ducts and vessels used for space heating, space cooling and hot water services; (b) providing fixed building services which— (i) a re energy efficient to a reasonable standard; (ii) have effective controls; and (iii) a re commissioned by testing and adjusting as necessary to ensure they use no more fuel and power than is reasonable in the circumstances. Intention In the Secretary of State’s view, requirement L1(a) is met in a new building by achieving both of the following. a. Unwanted heat losses from the building are limited by meeting the standards for all of the following. i. The building fabric, including walls, floors, roof, windows and openings – paragraphs 4.1 to 4.6 and paragraphs 4.9 to 4.14. ii. Airtightness – the required air permeability from Table 4.1. iii. The pipework and services – paragraphs 4.19 to 4.25. b. Unwanted heat gains to the building, throughout the year, through any of the routes listed in (a) above, are limited as set out in Section 4 and specifically for new buildings – paragraphs 4.16 to 4.18. 21 Building Regulations 2010 Approved Document L Volume 2, 2021 edition O N L I N E V E R S I O N