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

O N L I N E V E R S I O N R24-27C Industrial sites, workshops and non-residential agricultural buildings other than those with low energy demand 2.26 Special considerations may apply for industrial sites, workshops and non-residential agricultural buildings, where the National Calculation Methodology Modelling Guide cannot adequately account for the building’s use. For example, if using the National Calculation Methodology Modelling Guide would lead to negative impacts on cost-effectiveness and/or significant technical risk. Buildings with low energy demand 2.27 Buildings with low energy demand are taken to be buildings or parts of buildings, which are not exempt from the energy efficiency requirements for reasons outlined in Section 0, where any of the following apply. a. Fixed building services for heating and/or cooling are not provided. b. Fixed building services for heating and/or cooling are provided only to heat or cool a localised area rather than the entire enclosed volume of the space concerned (e.g. localised radiant heaters at a workstation in a generally unheated space). c. Fixed building services are used to heat space in the building to temperatures that are substantially lower than those normally provided for human comfort (e.g. to protect a warehouse from frost). 2.28 A target primary energy rate, target emission rate, building primary energy rate and the building emission rate should be calculated for non-exempt buildings with low energy demand. Zones corresponding to the definitions in paragraph 2.27 should be modelled as outlined in the National Calculation Methodology Modelling Guide paragraph 124 as ‘unconditioned’, i.e. not served by a space heating or space cooling system. 2.29 For a building with low energy demand both of the following apply. a. Every fixed building service that is installed should meet the energy efficiency standards set out in Sections 5 and 6. b. The building envelope should be insulated to a degree that is reasonable in the particular case. If some general heating is provided, as in paragraph 2.27c, then no part of the opaque fabric should have a U-value worse than 0.7W/(m2·K). 2.30 If part of a building with low energy demand is both: a. partitioned off b. heated normally (for example, an office area in an unheated warehouse), then the separately heated area should be treated as a separate building or zone and the normal procedures for demonstrating compliance should be followed. 2.31 If a building with low energy demand subsequently changes to a building that no longer has a low energy demand, consequential improvements may need to be made in some circumstances. See Section 12. 2.32 If a building or part of a building with low energy demand was designed as a shell and core building, and first fit-out work is carried out which results in it no longer being classed as low energy demand (in line with paragraph 2.24), then normal procedures for demonstrating compliance should be followed. 17 Building Regulations 2010 Approved Document L Volume 2, 2021 edition O N L I N E V E R S I O N