Since the mid 1970s, DOE has invested some $70 million in research and development at Lawrence Berkeley Laboratory (LBL) for energy-efficiency studies of advanced building technologies. That investment has helped spawn a $2.4-billion US market for key products -- energy-efficient lighting and advanced window coatings -- and efficiency standards for residential equipment and computerized tools for more efficient building design. By 1993 DOE's initial investment had reduced consumers' energy bills by an estimated $5 billion ($1.3 billion in 1993 alone). By 2015 the authors estimate that the products of that investment will save consumers $16 billion annually. But LBL research partnerships address a host of other building technology issues as well-building technology issues whose economic benefits are less easy to quantify but whose overall worth is equally important. They analyze public policy issues such as the role of efficiency options as a mitigation strategy for global climate change. They develop planning and demand-management methodologies for electric and gas utilities. They identify technologies and analytical methods for improving human comfort and the quality of indoor air. They contribute to the information superhighway. They focus on the special problems and opportunities presented by energy use in the public sector. And they do all these things at the local, national, and international levels. At LBL, they are part of the multi-laboratory, interdisciplinary approach to building technology research supported by DOE's Office of Energy Efficiency and Renewable Energy. They also participate in buildings-related research supported by DOE's Office of Health and Environmental Research, other federal agencies, and industry. This document describes LBL's role within this wider effort.