Building energy efficiency has been an important goal for decades. Since the energy crisis of the 1970s, much has been learned about how to improve energy efficiency in buildings. More recently, given increases in energy costs and concerns about the environmental impacts of buildings, there has been renewed emphasis on reducing building energy consumption. Over the same time periods, there has also been increasing awareness of indoor air pollution as a significant human health issue. The building community is challenged to reduce the environmental impacts of buildings, including energy consumption and greenhouse gas emissions, while maintaining indoor environments that are conducive to occupant health. A number of programs, standards, codes and other efforts are promoting, and in some cases requiring, the design and construction of green or sustainable buildings (ASHRAE 2009; USGBC 2009; GBI 2010; ICC 2010). More recently, there has been a focus on net-zero energy buildings (NTSC 2008). Some of these discussions also speak to high-performance, which generally includes a range of non-energy issues such as indoor air quality (IAQ). Nevertheless, many discussions of sustainable, high-performance buildings tend to focus on energy, which while critically important is only one aspect of performance and should not be pursued to the neglect of the others. This article considers the role of IAQ in energy efficient buildings and discusses how good IAQ can and should be factored into energy efficiency and other sustainable building goals.