Since replacing your windows should be the last action on your energy to-do list, first evaluate what other projects you should do first. Tackle the low cost, high impact projects first! If you are looking for a place to start, we recommend getting a Quick Home Energy Check or a Home Energy Assessment.
Replacing Windows
The Department of Energy, through its Energy Saver Do-It-Yourself (DIY) Projects offer easy, instructions to install exterior storm windows with low e-coating. It even has a shopping list!
Follow the ENERGY STAR window buying guide.
If you choose an ENERGY STAR-qualified window, frame material is already factored into the rating. But as a general rule of thumb, look for the lower U-factor, which describes the rate of heat flow through the window. Vinyl, wood, fiberglass, and some composites have lower U-factors than metal. Check the U.S. Department of Energy's webpage for more information.
If you have questions on the different types of glass and coatings, it may be best to seek the advice of a window professional. You’ll need to look at which side of the house the window faces and other factors. But here are a few key points to keep in mind:
- Windows with low-e coating can cost up to 15-30% more but can help reduce heat gain and save between 30-50% in energy cost.
- Windows can have either soft or hard low-e coatings. Soft coatings may peel over time, while hard coatings are more resilient.
- Windows may be filled with argon or krypton gases. These inert gases decrease the U-factor (lower U-factors are more energy-efficient), and therefore the rate at which heat moves through the window. Krypton is more expensive but more effective at slowing heat transfer.
