Energy Efficiency Information Sources

Efficient Windows Collaborative
Consortium of window and door manufacturers, industry suppliers, government agencies, and academic researchers, supported by Department of Energy, that promotes the use of energy efficient windows. Its web site features a great deal of useful information covering window energy performance issues. Detailed information is provided on different glazing and frame material options. Calculation tools show energy savings provided by various window types in various cities throughout the country. A calculator even allows data about an individual home to be entered, and shows what energy savings different window products can achieve.

Lawrence Berkeley Laboratories Windows & Daylighting Program
Supported by U.S. DOE, this research lab provides technical information on designing and selecting energy efficient window systems, including numerous software tools available for download:

  • RESFEN—Software designed to help consumers and builders pick the most energy-efficient and cost-effective window for a given application, whether it is a new home, an addition, or a window replacement. It calculates heating and cooling energy use and associated costs as well as peak heating and cooling demand for specific window products.
  • WINDOW—Software used to analyze/simulate thermal performance of window products.
  • THERM—Software for analyzing two-dimensional heat transfer through building products 

Information on LBL’s advanced research, including technical papers and details on new technologies such as highly-insulating windows and dynamic glazings is also available on Web site.

U.S. Department of Energy
Office of Energy Efficiency and Renewable Energy Building Technologies Program

The Building Technologies Program works to improve the efficiency of buildings and the equipment, components, and systems within them. The Web site describes R&D activities, and links to various tools, guidelines, training, and other resources.

Natural Resources Canada
Office of Energy Efficiency

The Canadian government offers a variety of information on choosing and installing energy efficient windows and doors to consumers.  It also administers Canada’s Energy Star for Windows program. 

Florida Solar Energy Center
Organization conducts research in building science, solar technologies and other energy technologies.  Its Web site features a section devoted to window technologies with a focuses on optimizing energy efficiency in sunny, air conditioned dominated climates.

If you’d like to add links to your organization to the Window & Door Green Resource Center, email