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 R43 Section 7: Air permeability and pressure testing 7.1 The minimum standard for air permeability of a new building is given in Table 4.1 of Section 4. 7.2 The building control body should be provided with evidence that test equipment has been calibrated using a UKAS-accredited facility or by the original manufacturer within either of the following periods. a. The previous 12 months. b. A period in accordance with manufacturer’s guidance. Calibration should be carried out in accordance with CIBSE’s TM23. It is recommended that test equipment is recalibrated at least every 24 months. 7.3 Building control bodies may accept a pressure test certificate as evidence that the building complies with regulation 43 of the Building Regulations. The building control body should be provided with evidence that the person who pressure-tested the building meets both of the following. a. Has received appropriate training. b. Is registered to test the specific class of building. 7.4 Buildings that are not dwellings, including extensions that are being treated as new buildings to comply with Part L, must be pressure tested except those types listed in paragraph 7.5. 7.5 The following buildings do not need to undergo pressure testing. a. Buildings with less than 500m2 total useful floor area. In this case the developer may avoid a pressure test, provided that the air permeability used to calculate the building primary energy rate and building emission rate is taken as 15m3/(h·m2) at 50Pa. b. A factory-made modular building that meets the following criteria: i. the floor area is less than 500m2 ii. the building has a planned service life of more than two years, where the intended time of use in a single location is less than two years iii. no site assembly work is needed other than linking standard modules using standard link details. If the building as installed conforms to a standard configuration of modules and link details for which the installer has pressure test data, this test data may be used to estimate the air permeability. Test data must be from a minimum of five in-situ measurements of the same module types and link details as used in the actual building. Air permeability should be in m3/ (h·m2) at 50Pa. When calculating the building primary energy rate and building emission rate for a factory-made modular building as described above, the value that should be used for design air permeability is the average air permeability test result at 50Pa plus 1.0m3/(h·m2). 57 Building Regulations 2010 Approved Document L Volume 2, 2021 edition O N L I N E V E R S I O N