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

RO6N L, I RN E2 V2E R, SRI O2N3(1), L1(a) Material change of use and change to energy status 11.5 A material change of use, in relation to buildings other than dwellings, is when a building satisfies any of the following: a. is used as a hotel or a boarding house, where previously it was not b. is used as an institution, where previously it was not c. is used as a public building, where previously it was not d. is not described in classes 1 to 6 in Schedule 2, where previously it was e. contains a room for residential purposes, where previously it did not f. contains at least one room for residential purposes, having previously had a greater or lesser number of rooms for residential purposes g. is used as a shop where previously it was not. 11.6 A change to energy status is when a building was previously exempt from the energy efficiency requirements but now is not. The change to energy status applies to the building as a whole or to parts of the building that have been designed or altered to be used separately. For example, when a previously unheated space becomes part of the heated building. NOTE: A material change of use may result in a change to energy status. 11.7 If there is a material change of use and/or a change to energy status, elements should satisfy all of the following. a. Existing thermal elements should meet the standards as outlined in paragraphs 4.7 to 4.8. b. If both of the following apply to existing windows, roof windows, rooflights and doors (controlled fittings), they should be replaced to meet the limiting standards in Table 4.1. NOTE: This does not apply to display windows or high-usage entrance doors. i. They separate a conditioned space from an unconditioned space or the external environment. ii. They have a U-value higher than either of the following. • For windows, roof windows and doors – 3.30W/(m2·K). • For rooflights – 3.80W/(m2·K), calculated by following paragraph 4.4. In addition, all of the following should be met. a. New or replaced thermal elements should meet the standards in Table 4.1. b. New or replaced windows, roof windows, rooflights and doors (controlled fittings) should meet the standards in Table 4.1. c. The area of openings in the newly created building should not be more than 25% of the total floor area. A larger area of openings may be achieved by following paragraph 11.8. d. Any fixed building services including building automation and control systems and/or on-site electricity generation that are provided or extended should meet the standards in Sections 5 and 6. NOTE: Consequential improvements may be required when there is a material change of use or change to energy status and Section 12 should be followed. 79 Building Regulations 2010 Approved Document L Volume 2, 2021 edition O N L I N E V E R S I O N