Air tightness testing, also known as air permeability testing or blower door testing
This was included in Part L of the building regulations in 2010, as part of the government’s scheme to conserve fuel and power.
Ensuring the air tightness of a property is at an appropriate level is not only part of building regulations, but also vital for ensuring that both heat doesn’t leak too quickly from a property while there is still enough ventilation to prevent stagnant air and the risk of damp and mould forming.
“Air Tightness” is defined in Approved Document F to mean how resistant the envelope of a building is to air entering or escaping the building while all other ventilation, like windows, vents and doors, are closed.
Do you need an Air Tightness Test?
All new build commercial properties that are over 500m² are required to have an air tightness test carried out.
All new build and converted residential properties require an air tightness test.