Premature building failures and increased heating and cooling loads have made building envelope air leakage a growing concern in North America. In Canada, the National Air Barrier Association has made the inspection and testing of air barrier systems a mandatory requirement within its Quality Assurance Program. In the United States, Massachusetts is the first of what is expected to be many states introducing revised Energy Codes making air barriers mandatory in new construction. The Air Barrier Association of America has recently formed and will adopt a similar quality assurance program. Utilizing existing ASTM standards, this paper proposes a protocol for the inspection and testing of air barrier systems to be performed before construction begins, during installation, and post-construction. Studies show that even routine testing of the air barrier system will dramatically improve a building's air permeance.