As part of a sustainable environment, buildings play an important role in both energy use and human well-being. In the United States, buildings account for more than 40% of the total energy consumption, and people spend 90% of their time in indoor environments. Given the pressing need to understand the energy performance of buildings to improve energy efficiency and indoor environmental quality, I see critical research needs to understand how the tradeoffs between energy use and indoor air quality, and the co-benefits of the two. Broadly, I am eager to carry out experimental and numerical studies on energy and health impacts of the building environment.