Air Permeability Testing has numerous names which are used interchangeably within construction. The most common names in circulation include: air testing, air loss testing, air leakage testing, air pressure test, blower door and fan testing. In principle all these names mean the same thing: Air Permeability Testing and correspond to particular procedures of testing and standards detailed in multiple areas of legislation. Air pressure testing calculates the air tightness of a building, known as its ‘air permeability’ or ‘leakage’ rate. For most (even professionals), this can be very confusing especially when asked by a Building Control Officer to provide certification that the construction meets the required standards.

Part L1A and L2A (England & Wales), Section 6 (Scotland) or Part F1 (Northern Ireland) of The Building Regulations require Air Pressure Testing. Air Pressure Testing has been mandatory for all new build residential and commercial properties in England, Wales and Northern Ireland since 2006, and in Scotland since 2010.