National Research Laboratories

The Buildings Technology Center (BTC) at Oak Ridge National Laboratory

http://www.ornl.gov
The premier U.S. research facility devoted to the development of technologies that improve the energy efficiency and environmental compatibility of residential and commercial buildings.

Lawrence Berkeley Labs

http://www.lbl.gov
http://www.radsite.lbl.gov/radiance for lighting design simulation
Conducts research in lighting design and studies on material performance with regards to energy efficiency.

The Florida Solar Energy Center (FSEC)

http://www.fsec.ucf.edu
The energy research institute of the State of Florida. The Center is nationally recognized for comprehensive programs in solar energy and energy-efficiency. On-line reports on research for building performance. Also thorough information on planning photovoltaic systems.

The Environmental Protection Agency (EPA)

http://www.epa.gov/buildings
Has several applicable sites relating to environmentally preferable product development and energy efficiency. The Energy Star web site is a good start to what they offer for building design.