With energy costs continuing to rise, minimization of air leakage is back in the spotlight. What does this mean in practical terms? How do you design for it? How do you implement it in the field?

Modern construction practices are increasingly embracing the concept of an air barrier within a building envelope design. Many high performance buildings now in operation owe their success largely to this passive and hidden system. Although it may appear new, the air barrier design concept has been in use in many U.S. jurisdictions and Canada for the better part of three decades. The idea was developed widely during the energy crisis of the 1970s when engineers and researchers were devising ways to improve the energy performance characteristics of buildings, particularly in colder climates. The need for high performance buildings led to, among other things, the concept of super insulated walls that separate exterior and interior environmental conditions and prevent the uncontrolled mixing of the air on either side through the use of an air barrier.

From material selection and proper detailing, to construction quality control and commissioning, numerous factors contribute to the effectiveness of an air barrier and its ability to reduce energy consumption. The concept is not complicated but does require attention to detail by all parties involved in the design-construction process. With buildings estimated to consume 40 percent of the nation’s primary energy in 2010, the importance of air barriers is ever increasing.