Project: Replace your windows
The final step in energy efficiency improvements.
Many people believe that energy efficiency starts with replacing windows. And while windows are very important (and an energy audit may recommend replacement), a wiser strategy is to take care of all the smaller projects first. Caulk, weatherstrip, install a programmable thermostat, etc. Once you’ve taken care of everything else, decide if making the investment in new windows is right for your home.
Montgomery County residents can get a $250 Property Tax Credit when energy-efficient windows are installed in a primary residence.
Pepco rebates for windows, up to $2,000. Must have an energy audit first.
Which window frame material is the most energy efficient?
If you choose an ENERGY STAR-qualified window, you don’t have to worry — 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 ENERGY STAR website for more information.
There are so many different types of glass and coatings. How do I know which is best for me?
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.
For more details, visit the Types of Window Glazing or Glass page on the U.S. Department of Energy’s website.