(Editor’s note:  For readers who were unable to participate in the Kearsarge Climate Action’s “WindowDressers” project, described in earlier 2023 issues of The Beacon, here’s some information about how to “do it yourself.”)

Larry Chase: What got you interested in insulating window panels?

Steve Darling: When we built our house in 2010, we installed roof windows, or skylights, to add light to the second story. After the first winter, we realized there was a lot of heat loss through those windows. I found that to buy and install insulated window shades would cost in the range of $10 to $15 per square foot of window area.  

Thinking that there might be a less costly approach, I searched the internet and found a site in Maine that provided do-it-yourself instructions for making simple, light-weight, and inexpensive interior insulating window panels.

LC: Had you made anything like this before, and did you find it difficult?

SD: I had no experience with anything like this, but once I got going on making them, I found it very manageable, as long as I took my time, followed the online instructions, and kept everything all neat and clean. 

LC: How much time did you invest in making the panels?

SD: I made 10 insulating panels, which took 9 to 10 hours total; therefore, each one took slightly less than an hour to make.

LC: At the time you made these panels, what was the cost of materials?

SD: The total cost in 2016, when I made them, for the wood, tape, screws, film, foam strips, and glue, was $141.15.

LC: You said that you made 10 panels. Were they all the same size?

SD: No, they were three different sizes. Therefore, I figured the area for all 10 in square feet (80.8), then divided that into the material costs ($141.15); that resulted in a cost per square foot of $1.75. As you can see, there were significant savings compared to the $10 to $15 per square foot for insulating window shades.

LC: So, you have had those 10 panels installed since 2016. Have they done the job you expected?

SD:  For the first five years I tracked my propane usage, and I found that, on average, I used 22 fewer gallons each year. With propane at that time averaging about $3.50 per gallon, I saved $77.00 per year. This means that I paid for my materials in two years.

LC: What do you see as the pros and cons of these window panels?

SD: On the pro side, they are low cost, easy to install/uninstall, very light weight, and require no mounting hardware. And, more important, they seal out air leaks, increase window R-values, and eliminate drafts caused by cold air movement.

On the con side of things, they require time and labor to make, and they are fragile. Fortunately, I have only had one damaged by a cat where I had to replace one layer of the film.

LC: Was this project part of a larger project?

SD: The bigger project was insulating all of the other exterior windows, most of which were done by installing “Window Quilts,” a product made in Vermont that I installed. Then I learned about the window panels provided by WindowDressers in Maine (the nonprofit guiding the current project described in previous Beacon issues) to do the remainder of those difficult skylights.
                                                                                   
(Steve and Gisela Darling have lived in Andover since 1977.Their local activities include The Andover Community Hub, the Friends of the Northern Rail Trail, the Andover Energy Group, and the New England Healing Sports Association, among others.)