Air tightness testing is compulsory in England and Wales under Part L1A of Building Regulations 2006.
In December 2007, RMP Acoustic Consultants and Building Test Services Ltd in Devon embarked on a new partnership offering combined air tightness and pre-completion sound insulation testing. Phil Wright of the Building Test Services is a fully accredited member of the British Institute of Non Destructive Testing. Upon completion of a successful air tightness test an iATS certificate can be issued.
Air leakage can contribute to up to 10% of heat loss in buildings as well as occupants dissatisfaction. Gaps and cracks in the building envelope are often difficult to detect by visual inspection, as they can be obscured by internal building finishes or external cladding. The alternative method is to measure leakiness of the building fabric as a whole.
Air tightness testing involves connecting a fan or a number of fans to a doorway or another suitable aperture in the building envelope. Air volume flow through the fan and the building pressure differential inside and outside are recorded. A relationship between air flow and pressure differentials allows to then calculate the leakiness of the building envelope.