Here’s How to Winterize Windows the Easy Way

Updated: Jan. 24, 2024

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No matter where you set the thermostat, if your windows are a sieve for the cold outside air, your home is not ready for winter and you’re going to feel a draft all season long. Fortunately, there’s an easy way to address that problem without having to undertake the expensive of replacing your windows entirely.

Why It’s Important to Winterize Windows

The most obvious reason for winterizing your windows is to stay warm. Drafty windows let in the cold air, and that can make your favorite corner or even your entire house uncomfortably chilly.

There’s an added benefit of energy efficiency. Your furnace is going to be working overtime to hit its mark on the thermostat if it has to battle a constant inflow of cold air from the windows. Energy bills are expected to be especially high this winter, so winterizing your windows will help you save money.

Also, check how to winterize your home and protect your possessions from the ravages of harsh winter.

How Much Does It Cost to Winterize Windows?

The cost to cover an average 3-foot x 5-foot window is between $1.50 and $3.00, depending on which kit you choose. Other factors to consider while pricing out your options is the size of your windows and how many you’re covering.

While energy savings vary greatly depending on how leaky your old windows are and your energy costs, you’ll certainly save enough by winterizing your windows with heat-shrink plastic to repay the cost, and in most cases you’ll save even more. But the real benefit may be in the added comfort this winterizing method brings by eliminating cold drafts.

There are other steps for winterizing windows that can add to the costs, like adding weatherstripping or re-caulking them.

How to Winterize Windows with a Kit

One of the easiest and most effective ways to winterize your windows is to add a sealed layer of plastic or glass over the window using an interior window insulation kit.

But before you leap into that, check the caulk seal around the outside of your window, starting with the exterior. A window insulation kit won’t help if there’s a leak around the window frame itself. Caulking your windows is another easy, cheap way to get your windows ready for winter.

Check the weatherstripping too. The moving parts of your window, the sashes, should have in-tact weatherstripping to seal them. Make sure the weatherstripping isn’t worn out, torn or missing. If if is, it’s easy to replace the weatherstripping on windows and doors.

With those steps done, you’re ready to open the window insulation kit and get to work. As for the kit itself, Duck brand Shrink Film Window Insulation Kit and 3M Window Insulator Kit are two readily available options that are easy to use and not too pricey.

Covering the entire window with a layer of heat-shrink plastic from one of these kits has two advantages. First, it completely seals the window, eliminating any air infiltration. And second, adding a layer of plastic creates an insulating layer of air that boosts the windows R-value.

The kits include double-sided tape that you apply to the perimeter of your window, usually on the window trim. Then you cut a slightly oversized piece of the plastic film and carefully adhere it to the tape. Complete the project by applying heat from a hair dryer to shrink the plastic film for a wrinkle-free installation. Finish up by trimming the excess plastic for a neat look. There’s even a way to keep your mini-blinds operational while the film is on your window.

There are a few downsides to this winterizing method, however. First, removing the sticky tape at the end of the season can cause damage to the paint or varnish on your trim. Also, the fact that this is a disposable solution makes it less environmentally friendly than a more permanent fix.

For a longer lasting solution, interior storm windows are a good alternative to heat-shrink plastic. Because they cover the entire window from the interior side, they have the same advantages of heat-shrink plastic, but will last decades. Interior windows are custom made to fit your window openings. Some fit into tracks, while others have compressible weatherstrip perimeters that allow a press-in installation.