I didn't realize there are so many variables build into choosing regular windows let alone the energy-efficient windows.
Why energy-efficient windows?
- It saves money and energy. Low E-coatings, gas fills and insulating spacers and framers can significantly reduce winter heat loss and summer heat gain.
- Protect from the winter and sun while also reducing condensation and interior fading. Frame and glazing materials that resist heat conduction do not become cold and this result in less condensation. Coatings on glass or plastic films within the window can significantly reduce the UV and other solar radiation which causes fading of fabric and furnishings.
- Keeps your home cooler in the summer and warmer in the winter. Windows temperature are more moderate and there are fewer cold drafts. Discomfort from strong summer sunlight is reduced.
- Rebates and credits for energy-efficient windows, doors and skylights.
The federal tax incentives for energy-efficient windows, doors and skylights, which is only good till 2007. But Congress will be voting to extend the provisions for residential energy-efficient property credits (when they return from President's day recess) on HR5351 - 'The Renewable Energy and Energy Conservation Tax Act of 2008.' None of the utility companies operating in our backyard of DC-MD-VA gives any rebates or incentives to name a few like in California, Colorado. The Federal tax incentives, via efficient windows collaborative.
- 10 percent of purchase price (not including installation cost)
- Must be installed in primary residence (not your second home)
- Max. credit is $200 for windows and skylights, $500 for doors - total max is $500
- Windows must be installed until Dec.31.2007 to qualify
- ENERGY STAR windows and skylights qualify, doors need manufacturers' statement to qualify
Tax credit is not the same as tax deduction like your 401(k) rather it is credited or use to offset tax owed, which works better than deductions.
There are important variables in the windows of the world.
- Each state have its own building code requirement. Depending on where you live, you might want to check out a couple of websites for more of the codes' information, 1) Energy Star and 2) Efficient Windows Collaborative, and 3) National Fenestration Rating Council.
- Understanding labeling: U-Factor, Solar Heat Gain Coefficient, Visible Transmittance, Air Leakage, Condensation Resistance. For explanation of the labeling terms, here.
- Energy Star windows has its own chart of key product criteria based on climate zone. Click on image to enlarge.
If you are still confused, to start with check out EFC website, where you can use the toolkit to compare energy savings and all the good criteria in choosing energy-efficient windows, even though it's designed for builders and designers. And go from there.