Air tightness testing is a recognised method of measuring the extent to which air in the building fabric is lost through leaks. Air leakage testing or air pressure testing is often made reference to as it.
Air leakage is the uncontrolled flow of air through fabric gaps and cracks (often referred to as infiltration or draughts) rather than ventilation, the controlled flow of air into and out of the building.
Too much air leakage results in the occupants having unnecessary heat loss and discomfort. Building regulations now place greater emphasis on the quality of the building’s fabric as the government strives to reduce CO2 emissions from new buildings.