Office of Sustainability

Windows

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Energy Efficient Windows

When Buying:

• Installing new windows can be expensive. Determine whether it will be more cost effective to invest in new energy efficient windows or to make energy upgrades to existing windows.

• Determine your Climate Zone to know the window requirements for maximum energy efficiency in your climate.

• Look for ENERGY STAR certified windows for your climate zone.

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Improve Energy Efficiency of Existing Windows

Window Treatments

• Awnings can reduce solar heat gain in the summer by up to 65% on south-facing windows and 77% on west-facing windows.

• Blinds—vertical or horizontal slat-type—are effective at reducing summer heat gain (up to 45% reduction in heat gain), but not winter heat loss.

• Drapes and Shades can be closed on summer days to reduce heat gain (up to 33%) and on winter nights to reduce heat loss (up to 10%).

Window Inserts

• Custom-fit panels placed on window interiors can drastically increase the thermal efficiency of single-pane and double-pane windows.

• Affordable and easy to install and remove.

Seal Air Leaks

• Sealing air links can save an old home 20% on heating and cooling bills.

• Caulk is used to seal air leaks through cracks, gaps, or joints less than 1/4 inch wide between stationary building components and materials.

• Use weatherstripping to seal the movable parts of doors and windows. Make sure to choose the proper weatherstripping for different applications.

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