Window Insulation: Does Window Film Work and Other DIY Myths

From cellular blinds to shrink-wrap window insulation film, there are a number of DIY window insulation tips meant to help take the chill out of drafty windows during the winter months. Window replacement is a big investment up front, so we understand the appeal of quick, affordable fixes that can get you through winter’s worst until you’re ready for a long-term solution.

We’ve broken down some of the top DIY window insulation tips, including inexpensive plastic window insulator kits, and present the pros and cons for each. Read on for a window expert’s take on temporary window insulation solutions from window film applications and self-stick weatherseal tape to insulating window treatment.

1.) Moment of truth: Does covering windows in plastic work?

Did you know that early window film applications were originally developed for NASA? We know what you’re thinking. If it’s good enough for the space program, it should be good enough for my house, right?!

Well, yes—sort of. The trick with plastic window insulation kits is that they’re only effective when installed correctly. And even then, they’ll help prevent heat loss through older, single-paned window glass, but they won’t help with heat loss through the window frame itself. And, actually, they are virtually ineffective on double- or triple-glazed windows.

How does window insulation film work? The sheet of plastic itself isn’t particularly insulating. Rather, it is the trapped air between the window and the plastic sheet which adds an insulating layer much like an extra pane of glass. The optimal size of air gap is between ⅜ and ¾ of an inch.

Proper installation is critical. You must have a continuous and smooth seal using the double-sided tape in order to trap the air effectively, otherwise air and water vapour will move between the glass surface and the plastic film, undermining the insulation efficacy.

Not only is installation finicky, time-consuming work (get ready to spend some quality time with your hair dryer to get rid of wrinkles in the plastic), but even the best installation will still result in a cling-film haziness that will obscure your view. And you’ll need to make sure that kids or pets don’t accidentally puncture the film or all your painstaking seal-perfecting work will be for naught.


  • Inexpensive
  • Works well on older, single-paned windows by adding an insulating pocket of air between the window glass and the plastic, which can reduce condensation, reduce heat loss, and decrease convective currents that cause cold drafts


  • Difficult to install correctly
  • Looks unattractive on windows and obscures visibility through the glass
  • Does not work on double- or triple-glazed windows

2.) Fast-fix for window frames: Self-stick weatherseal tape

Available at most hardware stores, adhesive rubber weather-sealing strips can be cut to the dimensions of any window frame and easily applied (just peel and stick) around the perimeter of the window frame to seal up gaps and reduce drafts.


  • Inexpensive and effective option to help seal up drafty window frames
  • Easy to install


  • Removing the strips may pull off paint or leave a sticky residue
  • Doesn’t do anything to improve the energy efficiency of the window itself

3.) Insulating window treatments: Practical solution or superficial coverup?

Insulating window treatments have come a long way since the days of those unsightly acrylic roller shades. Options like cellular shades, which use a series of cell pockets to trap air around your windows, or insulated curtains with built-in thermal backing add a layer of warmth and style to your tired, old windows.


  • Plenty of options to choose from including budget-friendly pre-cut designs or custom-fitted shades or drapes that match you home’s decor
  • Relatively easy to install
  • Can also be used to block out light for more restful sleep


  • High-quality or custom options can be expensive
  • To help reduce drafts, curtains and blinds must be closed at all times, which means blocking out cheerful sunshine during the day

The bottom line? While DIY window insulation hacks offer practical short-term solutions for your drafty window woes, nothing insulates your home as well as energy efficient double- and triple-paned windows.

When it’s time to pack up the plastic window film for good, we can walk you through all the energy efficient window options and help you choose the best window style to suit your needs and budget. Gienow’s window experts in Edmonton, Calgary, and Vancouver can also help you learn more about glass and glazing options so that you can rest assured that your window renovation project will be a rewarding investment in the overall comfort and value of your home for the long term.

Ready to say goodbye to drafty windows for good? Click and book a free estimate.