This paper discusses the development of building airtightness targets for the industrial, commercial, and orgnameal sectors in North America and considers both explicit quantitative targets as well as requirements for building configuration for testing.

Recommended, but nonmandatory, airtightness targets for building assemblies were first introduced in 1995 in Part 5 of National Building Code of Canada (Canadian Commission on Building and Fire Codes, National Research Council of Canada, National Building Code of Canada, Ottawa, 1995). In the United States, the U.S. Army Corps of Engineers (USACE) and the Air Barrier Association of America (ABAA) published its Air Leakage Test Protocol for Building Envelopes in 2012. This protocol has been used successfully to test hundreds of buildings and has permitted the USACE to develop quantitative targets for its buildings. Using the USACE protocol as a starting point, the ABAA then developed the Standard Method for Building Enclosure Airtightness Compliance Testing (Walpole, MA, 2015), which unlike many previous testing standards, recognized that two separate building configurations potentially are required when testing a building. Research projects conducted over the past five years have provided reliable results for the airtightness of new and existing buildings. These results show a broad spread in the degree of airtightness and have increased awareness of what is possible when proper due diligence is taken and have revealed the ramifications when it is not. Using this information, we proposed a series of large building airtightness targets and provided corresponding building configurations to be used for these tests.