Convention 2.03 - Air Permeability
Posted by Mike Gordon on 22 July 2015 08:58 AM

The SBEM default value of 25 m3/hr m-2 for all existing buildings shall be amended as follows:

Less than 10 m3/hr m-2 – only with an accredited air pressure test result

10 m3/hr m-2 – buildings > 500 m2 built to 2002 Building Regulations (or later)

15 m3/hr m-2 – buildings <= 500 m2 built to 2002 Building Regulations (or later) and buildings built to 1995 Building Regulations 25 m3/hr m-2 – buildings built to Building Regulations pre 1995

35 m3/hr m-2 – to be considered where buildings are pre 1995 regulations and where suitable evidence of high permeability exists, e.g. single skin metal clad structure within Planning Use Class B2 – B8 with large roller shutter doors and poor constructional details etc.