Integrating Indoor Air Quality and Energy Efficiency in Buildings William P. Bahnfleth Buildings are one of the largest energy end-use sectors in countries around the globe. Concerns for the availability of energy supplies and the impact of energy use on the environment are driving a worldwide focus on energy end-use reduction. In this push for dramatic changes in the energy use intensity of the building sector, it is essential that the fundamental importance of indoor environmental quality, particularly indoor air quality, not be lost. This presentation addresses 1) the significance of indoor air quality in terms of its impact on health and productivity and associated costs; 2) the inseparable linkage between indoor air quality and building energy demands, including examples of efficient technologies for maintaining good indoor air quality; and 3) the need for an approach to building research, design, and operation that recognizes this connection.