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

O N L I N E V E R S I O N Application 0.3 The guidance in Approved Document L, Volume 1 applies to dwellings only. In a mixed-use building, Approved Document L, Volume 2: Buildings other than dwellings should be consulted for building work in parts of the building that are not dwellings. NOTE: Dwellings are self-contained units. Rooms for residential purposes and buildings that contain only rooms for residential purposes are not dwellings; Approved Document L, Volume 2: Buildings other than dwellings applies. Common areas in buildings that contain multiple dwellings 0.4 For the common areas of buildings that contain more than one dwelling, the following guidance applies. a. If the common areas are heated, the guidance in Approved Document L, Volume 2: Buildings other than dwellings should be followed. b. If the common areas are unheated, individual fabric elements should meet the minimum standards set out in Section 4. New dwellings 0.5 Guidance for new dwellings is given in Sections 1 to 9 of this approved document, Approved Document L, Volume 1. 0.6 For a conservatory or porch installed as part of the construction of a new dwelling, the treatment of the conservatory or porch depends on whether both of the following have been achieved. a. There is adequate thermal separation between the dwelling and the conservatory or porch. b. The dwelling’s heating system is not extended into the conservatory or porch. If both (a) and (b) have been achieved, the conservatory or porch should be treated as if it were an extension being added onto an existing dwelling. The guidance for new elements in existing dwellings in Section 10 should be followed. If either or both of (a) or (b) has not been achieved, the conservatory or porch should be treated as a room in the new dwelling. The guidance for the whole new dwelling should be followed, including for dwelling primary energy rate, dwelling emission rate and dwelling fabric energy efficiency rate calculations. Extensions to and work on existing dwellings 0.7 Guidance for existing dwellings is given in this approved document for the following. a. Limiting heat gains and losses: Section 4. b. Building services: Sections 5 and 6. c. New elements in existing dwellings, including replacing a fabric element and constructing an extension: Section 10. d. Existing elements in existing dwellings, including renovating or retaining a thermal element, material change of use and change to energy status: Section 11. NOTE: For building work in very large dwellings of over 1000m2, consequential improvements may be required to improve the energy efficiency of the dwelling. Guidance is given in Section 12. 2 Approved Document L Volume 1, 2021 edition Building Regulations 2010 O N L I N E V E R S I O N