This article suggests that integrated whole-building design can yield superior comfort with about three to 30 times less mechanical energy and often with lower capital costs, but that achieving this poses fundamental challenges to professional education and practice and to compensation structure. The article provides a case study of the superefficient Pacific Gas and Electric home in Davis, California. This case study illustrates that if we properly count multiple benefits and take credit for those that are real and measurable in rigorous engineering-economic terms, we will very often find that the way to make a building inexpensive to construct is to make the windows expensive. This article was published in ASHRAE Journal, June 1995. Copyright 1995 American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. Reprinted by permission at www.rmi.org. This article may not be copied and/or distributed electronically or in paper form without permission of ASHRAE.