These guides examine the energy use impacts of new windows for homes in hot, mixed and cold climates. They show the the impact of orientation, window area, and shading. The energy use has been calculated for various window design variations including 5 orientations (equal, north, east, south, and west), 3 glazing areas, 20 glazing types, and 5 shading conditions.
Providing views, light, and fresh air represent traditional window functions that do not change fundamentally as new technologies are introduced and should be considered in the design process.
Efficient Windows Basics
Designing new homes can be a complex issue, but some straightforward principles and guidelines may help you set a solid foundation for window energy efficiency upon which you can further improve with careful design. Two of the most straightforward principles of selecting efficient windows are these:
- The windows must meet the locally applicable energy code requirements;
- Windows that are ENERGY STAR® qualified for the home’s climate ensure state-of-the-art energy performance even in locations with outdated or nonexistent energy codes.
Code-compliant windows, especially if ENERGY STAR qualified, offer benefits including energy cost savings, improved comfort, less condensation and fading, and the potential for HVAC downsizing.