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

O N L I N E V E R S I O N R23(2), L1(a) 10.11 When extending an existing dwelling with a total useful floor area of over 1000m2, consequential improvements may be required. Guidance in Section 12 should be followed. Conservatories and porches 10.12 A conservatory or porch must have thermal separation from the existing dwelling. If the thermal separation is removed or the dwelling’s heating system is extended into the conservatory or porch, the conservatory or porch should be treated as an extension and paragraphs 10.7 to 10.11 should be followed. 10.13 If the conservatory or porch is not exempt from the energy efficiency requirements (see paragraph 0.14), all the following elements should meet the minimum standards of paragraphs 4.7 and 4.8 and Table 4.2. a. New thermal elements. b. Replacement thermal elements. c. New windows, roof windows, rooflights and doors. The limitations on area of windows, doors and rooflights in paragraph 10.7d do not apply. In addition, both of the following should apply. a. Any walls, doors and windows should be insulated and draught-proofed to at least the same extent as in the existing dwelling. b. Fixed building services and/or on-site electricity generation within the conservatory or porch should both: i. meet the standards in Sections 5 and 6 ii. have independent temperature and on/off controls. Building Regulations 2010 Approved Document L Volume 1, 2021 edition 63 O N L I N E V E R S I O N