U.S. commercial building owners could save substantially on annual heating and cooling energy costs by improving airtightness of their buildings' envelope, according to a recent National Institute of Standards and Technology (NIST) study. The research used simulation software to evaluate the energy impact of improved air barriers in three typical non-residential buildings in five cities, each in a different climate zone. The results predicted potential annual heating and cooling energy cost savings as high as 37%.
With baseline energy, climate, and building data from each city, the researchers simulated conditions of a typical, two-story office building; a one-story retail building; and a four-story apartment building in Bismarck, ND; Minneapolis; St. Louis; Miami; and Phoenix. Each building was modeled with wood frame and masonry construction. Methods for increasing air tightness included building wraps or coatings for masonry blocks. The study focused on changes in energy expenditures as a result of increased airtightness, not on the methods themselves, so it does not single out a "best" airtightness method.