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

O N L I N E V E R S I O N Exemptions for covered areas 0.15 Where a dwelling is extended by adding a carport that is open on at least two sides, a covered yard, a covered walkway or a covered driveway, the work is exempt from the energy efficiency requirements if both of the following apply. a. The extension is at ground level. b. The floor area of the extension does not exceed 30m2. Live/work units 0.16 A building that contains both living accommodation and space for commercial purposes (e.g. for a workshop or office) should be treated as a dwelling if the commercial part can be reverted to domestic use. 0.17 The commercial part of a building can be reverted to domestic use if all of the following apply. a. There is direct access between the commercial space and the living accommodation. b. The commercial space and the living accommodation are within the same thermal envelope. c. The living accommodation comprises a substantial proportion of the total area of the unit. What constitutes a ‘substantial proportion’ should be assessed on a case-by-case basis by the building control body. NOTE: A large non-domestic building that contains a small flat for a manager is not treated as a dwelling. A dwelling that contains a room used as an office or utility space is still treated as a dwelling. Mixed-use developments 0.18 When constructing a dwelling as part of a larger building that contains other types of accommodation, sometimes called a mixed-use development, refer to the two volumes of Approved Document L as follows. a. For guidance on each individual dwelling, use this approved document, Approved Document L, Volume 1: Dwellings. b. For guidance on the non-dwelling parts of the building, such as heated common areas and any commercial or retail space, use Approved Document L, Volume 2: Buildings other than dwellings. Selected key interactions with other parts of the Building Regulations 0.19 The approved documents set out what, in ordinary circumstances, may be accepted as one way to comply with the Building Regulations. Those designing or undertaking building work remain responsible for assessing, on a case-by-case basis, whether specific circumstances require additional or alternative measures to achieve compliance with the regulatory requirements. There are interactions between many of the requirements of the Building Regulations. Guidance on some key interactions is given below. Interaction with Part C 0.20 This approved document, Approved Document L, Volume 1, provides guidance and examples on upgrading thermal elements. For interstitial and surface condensation, a lesser standard may be acceptable. Guidance in Approved Document C should be followed. 4 Approved Document L Volume 1, 2021 edition Building Regulations 2010 O N L I N E V E R S I O N