ASHRAE Technical Committee 4.5


Efficient Window Collaborative
Use the Efficient Window Collaborative web site to select energy-efficient windows and skylights for your location, and to learn more about features that make windows and skylights more energy-efficient.

Florida Solar Energy Center
The Florida Solar Energy Center studies the energy and illumination performances of fenestration systems.

Lawrence Berkeley National Laboratory – Windows and Daylighting
Lawrence Berkeley National Laboratory performs research on the energy-efficiency of fenestration, and publishes public-domain software to analyze the energy performance of windows, doors and skylights.

National Fenestration Rating Council
The mission of the National Fenestration Rating Council is to establish fair, accurate and credible information on the energy performance of windows, doors and skylights.

U.S. Department of Energy - Energy Star Windows
The Energy Star is voluntary program for residential windows that specifies qualifying product performance by climate zone.
U.S. Department of Energy - Windows R&D
The Building Technologies Program at the U.S. Department of Energy works in partnership with industry to develop the next generation of windows.

Purdue University - Architectural Engineering Laboratories and Center for High Performance Buildings 
The Architectural Engineering group and the Center for High Performance Buildings perform research on fenestration system design and controls, windows and daylighting, their impact on energy use and indoor environmental comfort, and integration with lighting and thermal systems.

University of Waterloo - Advanced Glazing System Laboratory (AGSL)and Solar Thermal Research Laboratory (STRL)
The AGSL and STRL are advanced laboratories of the University of Waterloo dealing with the solar optics and heat transfer of widows and other building energy efficiency technologies.