The older your home is, the less likely it is to have energy-efficient windows. Thankfully, the best window insulation kits are an affordable DIY solution that can significantly cut down on the cost of your energy bill and make your home less drafty.
So, how do you install window insulation film? Most of these kits work in the same basic way. You wipe down the window trim with a cloth and then apply the included double-sided tape, then you cut the plastic sheet to size (if necessary) and stick it to the tape, ensuring that there's an overlap of a few inches. Finally, you apply heat to the plastic with a blowdryer, so it has a shrink-wrap effect.
Note that while these kits are effective at minimizing your energy bill, they block access to your window for the season, so think of them as a temporary solution that's ideal for keeping heat in during colder months. For keeping the heat out during the summer, skip to the bottom of this article for a couple of options that allow you to more easily open your windows.
A kit's effectiveness is a tough thing to gauge because different brands use different materials and terms. For example, some brands talk about R-value (a measurement of a specific material's insulation performance) while others simply have products of varying thicknesses for different jobs. As a shopper, it's typically best to consult the reviews when comparing and contrasting; past buyers and their ratings will tell you almost everything you need to know about a specific kit's insulating abilities.
These are the three best window insulation kits to keep the heat in and the cold out — as well as two other options that help to maintain the temperature in your home year-round. But before you purchase any of these kits, always check the measurements to ensure the kit will work for your intended windows. The plastic can be cut to size, as can the tape, but if your window is bigger than the included supplies, the kit will ultimately be useless to you.
1. The Overall Best Window Insulation Kit
This kit from 3M is a best-seller with over 4,000 reviews and an overall rating of 4.4 stars. It's the ideal pick for most jobs because it insulates up to five windows in your home, and can be used for anything that's 5-by-3 feet or smaller. The brand boasts an R-value increase of 90% for a single-pane window, and reviewers seem to agree that it makes a noticeable difference. It's also "really easy to apply" and "lasts all winter."
One reviewer wrote: "I live in a 1st floor apartment in a building built in 1969 with original windows. In [New Hampshire] it can get very cold and this kit has paid for itself many times over, my heating bill is so much lower than previous winters, the cold stays out and the heat stays in."
- Windows insulated per kit: five (3 by 5 feet)
- Dimensions of plastic sheet: 61.92 by 210 inches
- Length of tape: 997 inches
2. The Most Affordable Window Insulation Film
At $7 each, this insulator kit from Duck is a steal — especially considering that it has a 4.4-star rating. Each kit comes with enough materials to insulate three 3-by-5-foot windows. The film is both clear and effective when it comes to blocking drafts, while the double-sided tape can be used safely on painted wood, finished wood, aluminum, or vinyl. Some buyers note that it's a bit more finicky than some more expensive brands, but for the price, it can't be beat.
One reviewer wrote: "The price is right, works wonders on our townhouse windows. There was plenty of film to do 3 windows as described. We haven’t had our usual -20 to -30 cold snaps as of yet, but it still has kept the cold night draft at bay."
- Windows insulated per kit: three (3 by 5 feet)
- Dimensions of plastic sheet: 62 by 126 inches
- Length of tape: 648 inches
3. The Best Heavy-Duty Option
For porches, extra-large windows, or poorly insulated areas, there's Duck brand's max-strength heavy-duty insulating film. It's made from a thick, puncture-resistant material that more effectively blocks drafts from thin glass — plus, it comes in one large sheet for use on especially big windows or patio doors. Since it's more durable than most of its competitors, it's great for pet-friendly households or high-traffic areas.
One reviewer wrote: "Our sun porch has 3 sliding doors (each 10') facing northwest so the room tends to get cold in winter. Most plastic is not heavy enough to keep out all the cold air and tears easily. These heavy-duty films are thick yet fairly see-thru and keep all the cold air out."
- Windows insulated per kit: one (7 by 10 feet) or two (4 by 6 feet)
- Dimensions of plastic sheet: 84 by 120 inches
- Length of tape: Brand does not specify (but it is included)
Also Great: A Year-Round Window-Insulating Solution
If you're looking for a solution that allows you to both insulate your windows and open them easily, opt for this insulating tape from yotache. It's made from thick, closed-cell foam on one side and has a self-adhering glue on the other, so you can weather-strip your windows without specialty tools (besides maybe scissors or a knife). Get the roll in two densities and more than a dozen sizes. [[Tweaked here since there are 19 sizes, so not "dozens." Be sure to check!]]
One reviewer wrote: "We have metal windows from the 80's and the original seal was no longer effective so our bedroom gets really cold at night. I was worry if the seal/padding was too thick that we might not be able to close the window so decided to order this and give it a try. We're happy the windows were locked properly and noticed [reduced] street noise and warmer room."
Also Great: The Best Thermal Curtains
These thermal curtains are another great option for year-round insulation, plus they add to the aesthetic of your home. The extra-thick, triple-weave fabric blocks out up to 99% of light, not to mention it helps to balance sound, heat, and cold. The set of two is available in six sizes and almost two dozen color options.
One reviewer wrote: "These curtains are all throughout our home. We love them, and they definitely block out the sunlight. We used them to help keep our energy bills down in the summer, and they made a big difference in temperature in rooms with lots of sun. They are also thermal and help hold in the warm air from our cold windows in the winter."