Does Putting Plastic Over Your Windows Really Save Energy?

Does plastic window film save energy?


When you’re dealing with old, drafty windows, you essentially have two options: replace them or seal them with insulating window film—a.k.a. plastic wrap. This kit by 3M—a leader in consumer products—insulates up to five windows, and the company claims it lowers heating costs and saves energy. But is that true?

According to Energy Star, the government program launched by the Environmental Protection Agency (EPA), the answer is yes. Depending on where you live, sealing up leaks throughout the house can cut your utility bills up to 20 percent. Their website says that in order to fully feel the effects of window insulation kits—on your skin and in your wallet—you have to make sure to shrink-wrap the plastic coverings. You can do this by using a heat source like a hair dryer while installing the film.

If you’re not sure whether plastic window insulation kits are necessary in your home, Energy Star says to look out for these signs: “rattling windows, visible gaps around the window or door trim, noticeable pests and dust entering through gaps or holes in or around the window or door, odors from the outside entering the home and peeling paint around the window or door frame.”

Energy Star also suggests these tests:

  • The paper test: Close the window on a piece of paper and see if it easily moves back and forth; this would indicate it’s not shutting tightly enough. In a case like this, weather stripping is recommended.
  • The incense test: Light an incense stick, then hold it next to the seams or sash of your window. Does the smoke waft in a particular direction? If it favors one side, you most likely have a leak.

If you want to be extra careful, you can hire a professional to come over and do a home energy audit.

If you want more information about home energy audits, check out this guide.

Photo: Courtesy of 3M