reg 21 Application of energy efficiency requirements
(1) The energy efficiency requirements apply to— (a) the erection of any building of a kind falling within this paragraph; (b) the extension of any such building, other than an extension to which paragraph (4) applies; and (c) the carrying out of any work to or in connection with any such building or extension. (2) A building falls within paragraph (1) if it— (a) is a roofed construction having walls; (b) uses energy to condition the indoor climate; and (c) does not fall within one or more of the categories listed in paragraph (3). (3) The categories referred to in paragraph (2)(c) are— (a) buildings which are— (i) listed in accordance with section 1 of the Planning (Listed Buildings and Conservation Areas) Act 1990 or section 76 of the Historic Environment (Wales) Act 2023 ; (ii) in a conservation area designated in accordance with section 69 of the Planning (Listed Buildings and Conservation Areas) Act 1990 or section 158 of the Historic Environment (Wales) Act 2023 ; or (iii) included in the schedule of monuments maintained under section 1 of the Ancient Monuments and Archaeological Areas Act 1979 or section 3 of the Historic Environment (Wales) Act 2023 , where compliance with the energy efficiency requirements would unacceptably alter their character or appearance; (b) buildings which are used primarily or solely as places of worship; (c) temporary buildings with a planned time of use of two years or less, industrial sites, workshops and non-residential agricultural buildings with low energy demand; (d) stand-alone buildings other than dwellings with a total useful floor area of less than 50m 2 . (4) This paragraph applies to any extension of a building falling within class 7 in Schedule 2 except a conservatory or porch— (a) where any wall, door or window separating the conservatory or porch from that building has been removed and not replaced with a wall, door or window; ... (b) into which the building's heating system has been extended to heat the conservatory or porch; or (c) in which a fixed heating appliance has been provided to heat the conservatory or porch. (5) In this regulation, the following terms have the same meaning as in European Parliament and Council Directive 2010/31/ EU of 19 May 2010 on the energy performance of buildings (recast) — (i) “industrial sites”; (ii) “low energy demand”; (iii) “non-residential agricultural buildings”; (iv) “places of worship”; (v) “stand-alone”; (vi) “total useful floor area”; (vii) “workshops”.