Uncontrolled air leakage commonly occurs at interfaces between construction materials and service penetrations. It can have a negative impact on comfort, health and energy. As such control of air leakage is a fundamental part of an energy efficient design strategy. During the design process it is important to identify the primary air barrier elements. Good quality design detailing is required. During the construction process it is important that the builder fully understands the air tightness details and responsibility for construction and the related quality control procedures are clearly established. Intermediate air pressure testing may form part of the quality control procedures in order to check if any issues exist and allow remedial works to be carried out at an early stage. The acceptable construction details (ACD’s) will be required as evidence to show the thermal performance details have been constructed as per the design. These also contain checks for the air barrier and should be signed by the responsible supervisor of the works. See below link to the ACD’s for wall insulation as an example.