Resources for Historic Homeowners

John Leeke's Historic HomeWorks™ Question & Answer Column

#28 Interior Storms

Last winter our windows were drafty and cold. We don’t have the time or money to mount a major window restoration project before winter sets in again. What can we do to improve our existing windows for the coming winter?

Have you heard about the clear film you tape over your windows to keep the cold winter drafts out? You can get kits down at the hardware store with everything you need.

Here at my house I tried out a couple of the shrink wrap film kits, but didn't like ripping them out and throwing them away at the end of the heating season. At five bucks per window per year it looked more like a way for the manufactures to fill their corporate coffers than a way for me to save on energy costs. Plus the tape damaged the finish on the window casings. I resolved to make a simple air panel system that would reused the plastic film, that any handy Do-It-Yourself person could make, that would last for years, not damage the window in any way (good for the museum houses), would cost less than $10 in materials, take less than an hour to make, and take less than a minute to remove and install each season.

So I made simple wood frames and taped the plastic film to the frame. Then I applied a gasket around the edge. The whole frame is sized to fit snugly into the reveal of the window, just to the inside and up against the sash. The seal is so good that when the wind blows the panel pops right out, so I hold them in place with screws. I decided the kits from Warp and 3M were too costly at about $10 for two windows. (I've got 26 windows and that would be $130 each year, so forget it!), I bought a whole roll of graphics-grade shrink wrap film for $60 at the art-supply house. I'm not sure how much is in the roll, but it looks like a 50-year supply for my entire neighborhood. Those big corporations are making a killing on their $10 kits. I figure there can't be more than about sixty cent's worth of plastic film in each kit. I have made three rounds of these "air-panels" over the years with minor improvements each time.

My wife says "they make the front parlor much more comfortable in the winter, and cut down on the exterior street noise too." My friends say, "Neat! Can you make 38 of them for my house?" I say, "Make your own, here’s how."

I make simple wood frames of straight grained pine stock 3/4" x 1", with sheetrock screwed butt joints and a horizontal rail at the same height as the window sash meeting rails. I use double stick tape to fasten shrink wrap plastic film on one face of the frame. It would be possible to put another piece of plastic on the other side of the frame, but I don't bother. Around the 3/4" edge of the frame I apply a gasket or weatherstripping. The whole frame is sized to fit snugly into the reveal of the window, just to the inside and up against the sash, with the weatherstripped edges fitting against the interior stops, the stool at the bottom and the header stop at the top. I shrink the plastic after the frame is installed for the first time.

See the step-by-step instructions and ask questions about making air panels at the Historic HomeWorks internet Forum:

You can buy pre-made interior air panels and storms from:

Windo Therm
PO Box 405
90 Church Street
Hoosick Falls , NY 12090
(800) 819-9463
(518) 686-9581

Interior Window Insulating Panels using a double shield of clear glazing film on a narrow metal frame.

David Degling
Innerglass Window Systems
15 Herman Drive
Simsbury , CT. 06070
(860) 651-3951
(800) 743-6207

Innerglass Interior Storm Windows are commercial quality glass windows with vinyl extrusions installed on the interior side of the window.


John Leeke is a preservation consultant who helps homeowners, contractors and architects understand and maintain their historic buildings. You can contact him at 26 Higgins St., Portland, Maine, 04103; or by E-mail:; or log onto his website at:

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