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

O N L I N E V E R S I O N AA • The energy prices that are current when the *Thermal element Defined in regulation 2(3) and application is made to the building control body 2(4) as follows. should be used when evaluating energy savings. 2(3) In these Regulations “thermal element” means Current prices are given on the BEIS website, at: a wall, floor or roof (but does not include windows, https://www.gov.uk/government/collections/ doors, roof windows or roof-lights) which separates quarterly-energy-prices. a thermally conditioned part of the building (“the Space cooling system A system for cooling the conditioned space”) from— temperature of the air in a space. a. the external environment (including the Specialist process lighting Lighting to illuminate ground); or specialist tasks within a space rather than the space b. in the case of floors and walls, another part of itself. Specialist process lighting includes theatre the building which is— spotlights, projection equipment, lighting in TV and photographic studios, medical lighting in operating i. unconditioned; theatres and doctors’ and dentists’ surgeries, ii. an extension falling within class 7 of illuminated signs, coloured or stroboscopic lighting, Schedule 2; or and art objects with integral lighting, such as iii. where this paragraph applies, conditioned sculptures, decorative fountains and chandeliers. to a different temperature, Standard Assessment Procedure The current and includes all parts of the element between the approved procedure for assessing the performance surface bounding the conditioned space and the of dwellings in line with this document (Approved external environment or other part of the building Document L, Volume 1). The Standard Assessment as the case may be. Procedure is detailed in The Government’s Standard Assessment Procedure for Energy Rating of 2(4) Paragraph 2(3)(b)(iii) only applies to a building Dwellings version 10. which is not a dwelling, where the other part of the building is used for a purpose which is not similar or Target emission rate The maximum CO emission 2 identical to the purpose for which the conditioned rate for the dwelling, expressed as kgCO /(m2·year) 2 space is used. and determined using the Standard Assessment Procedure. Thermal envelope The combination of thermal elements of a building that enclose a particular Target fabric energy efficiency rate The minimum conditioned indoor space or group of indoor dwelling fabric energy efficiency, expressed as spaces. kWh/(m2·year) and determined using the Standard Assessment Procedure. Thermal separation Occurs where a dwelling and a conservatory or porch are divided by walls, floors, Target primary energy rate The maximum primary windows and doors to which one of the following energy use for the dwelling in a year, expressed as applies. kWh /(m2·year) and determined using the Standard PE Assessment Procedure. • The U-values are similar to, or in the case of a newly constructed conservatory or porch not Thermal bridging Occurs when part of a thermal exceeding, the U-values of the corresponding element has significantly higher heat transfer than exposed elements elsewhere in the dwelling. the materials surrounding it. 7766 AApppprroovveedd DDooccuummeenntt LL VVoolluummee 11,, 22002211 eeddiittiioonn BBuuiillddiinngg RReegguullaattiioonnss 22001100 O N L I N E V E R S I O N