Windows are an essential feature of any home – for sunlight, cool breezes, a view of the neighborhood –but they’re potentially a huge cause of energy loss. On average, 25-30% of heat gain or loss is through windows, forcing your HVAC system to work harder, shortening its life, and costing you thousands of dollars in unnecessary bills.
How do you know if you have a problem? If your windows are over 20 years old, they may have deteriorated enough to leak water or air. On a chilly day, are they cold to the touch? Is there condensation on the interior of your house? Are there cracks in the caulking and glazing (the putty that holds panes in place)? A couple of DIY tricks to try: hold a candle or incense stick near the window – if wisps of smoke waver or disappear, there’s a leak. Or go outside after sunset and have a person inside shine a flashlight at the window frame. If you see pinpoints of light, there’s another leak.
To fix problem windows, you have one of two routes: repairing/updating existing windows or replacing them. Several factors may favor repairing rather than replacing, starting with the huge difference in cost. Caulking, weatherstripping, and hanging energy efficient window coverings costs very little. Properly-fitted storm windows can insulate you from wind and weather as effectively as modern windows at half their price, and avoid landfilling existing windows that are likely made of superior materials. The Dept of Energy’s “Update or Replace Windows” can help you determine what’s best for you. For more information on storm windows, check out Energy Saver Storm Windows and Energy Star Storm Window Product Guide.
A special note to residents of historic/conservation districts or a historic landmark home: you should focus on rehabbing windows to make them functional and contact your city’s historic preservation department before replacing them. The good news is that tax and cost-share incentives can help cover your costs. Check Iowa’s Historic Preservation Tax Credit (25%) or Iowa City‘s Historic Preservation Fund to learn more.
If your windows are deteriorated beyond repair, and replacement is the only option, keep these factors in mind when shopping for new ones:
- For Iowa’s cold winters, consider selecting double-paned, gas-filled windows. Modern window technology seals an inert gas (a far better insulator than just air) between the panes of glass;
- Look for the Energy Star sticker on the window, indicating that heat loss (U-value) and heat gain (the Solar Heat Gain Coefficient, or SHGG) through the glass is low. Select windows with both low U-factors and low SHGCs to maximize energy savings in temperate climates with both cold and hot seasons;
- Proper installation by qualified contractor is important. While window repair can be DIY, skilled installation of windows is widely regarded as important as the quality of the window itself;
- New windows are expensive. An internet search indicates that 2023 average replacement costs are $700/window, ranging from $300 up to $1200 based on window materials, brand, style, and labor costs. A one-to-one return on your investment in terms of energy you will save is very unlikely.
Fortunately, new windows, skylights, and doors (not installation costs) can qualify for a 30% income tax deduction, limited to $600/year. Phased replacement of windows over several years allow the taxpayer to repeatedly capture tax credits up to $600 annually. The windows must be installed at the taxpayer’s primary residence and be energy-efficient certified by manufacturer, or have the Energy Star label, so keep your purchase documentation. File Form 5695 (Residential Energy Credits) or talk to your tax preparer. For more information, check out the Inflation Reduction Act incentives here.
Read the entire Good Energy Fall 2023 Issue