Windows are where we often look to improve the energy performance in old homes. But don’t rip out those old sashes yet. A field study in Vermont suggests that “remove and replace” is not necessarily the way to go when it comes to old windows.
Our study of old windows showed that the energy savings are similar for a variety of retrofit and replacement strategies. Rates of return on investment for energy improvements are quite low when starting with typical or tight windows with storms in place, but are significantly higher when renovating loose windows with no storm.
The difference in annual energy savings between renovating an old sash and replacing it with a new one was very small–retrofits saved only a few dollars.