One of the best things to do on a cold winter day is to relax inside your warm, comfortable home. But that can become unpleasant quickly if your house has drafty windows. Luckily, there are many low-cost and easy ways to insulate your windows that are effective at keeping your home cozy.

This guide on how to insulate windows walks you through the five different options to help you determine what is best for your home.

Why Should You Insulate Your Windows?

Insulating your windows is necessary for energy efficiency in your home. They’re a major source of heat loss in the winter and heat gain during the summer. By properly insulating your windows, you can reduce this heat transfer, making your home more energy efficient and reducing energy costs.

Window insulation also helps to control condensation, reduce noise, and increase the overall comfort of the home.

What Are the Best Ways To Insulate Your Windows?

While there’s no shortage of options for insulating your windows during winter, the best method for your home depends on various factors. Some of the best types of insulation for windows include caulk, draft stoppers, thermal curtains, weather stripping, and window film.

This comparison chart offers a quick snapshot of what methods might work best for your home, are easy to do, and are the most affordable. Depending on the climate where you live, effectiveness is also an important factor to consider — insulating for a breezy Florida cold snap isn’t the same as doing so for a long, snowy Minnesota winter.

Type Of InsulationWorks forCostRelative EaseRelative Effectiveness
CaulkOutdoor gaps$10–$15✶✶✶✶✶✶✶
Draft StopperWindowsills and doors$10–$25
Thermal CurtainsAll windows$20–$100✶✶✶✶✶
Weather StrippingWindows that need to remain functional$5–$15✶✶✶✶✶✶
Window FilmWindows that don’t need to be operational$5–$10✶✶✶✶✶✶✶

Option 1: Caulk Your Windows

Temporary caulking is one of the most cost-effective and easiest ways to winterize drafty windows. Start by applying caulk around the exterior of leaky windows. You’ll also need to seal any cracks between the wall and interior trim of the window.

person applying caulk to a window for added insulation

Pricing: You can pick up a tube of temporary caulking for anywhere between $10 and $15 per tube. If you don’t have a caulking gun, you’ll need to purchase one — they cost about $10 on average. One caulking tube will be enough to seal around three standard-size windows, inside and out.

Ease of installation: Running beads of caulk is straightforward. It’s a forgiving material, and pretty much anyone can manage to effectively caulk. Apply a quarter of an inch line of caulking around the perimeter of your window and window panes. Follow behind with your finger or a caulk finishing tool to smooth the bead of the caulk — this will provide a good seal.

Effectiveness: Sealing your windows with caulking is extremely effective and can prevent virtually any draft caused by gaps in your windows. If you seal with caulk, you’ll notice a difference in temperature and save money on energy bills.

My opinion: Caulking around your windows is a solid option for weatherproofing your windows. It’s inexpensive, installation is easy, and it’s very effective. Just remember, you need to use temporary caulking. It works similarly to other caulk, but it’s easier to remove in the warmer months when you’ll want to open your windows again.

Read Also: How to weatherproof windows

Option 2: Lay Down a Draft Stopper

A draft stopper (sometimes known as a draft snake or draft blocker) is a cloth tube stuffed with batting, beans, corn, or other weighted material. Set draft stoppers around windows or doors to block any cold air from entering through cracks and prevent warm air from escaping.

child and dog sitting in front of a window with a draft stopper
Credit: Amazon, KAKICLAY Store

Pricing: Draft stoppers can be purchased for $10–$25. However, you can easily create simple DIY or homemade draft stoppers, which can significantly bring down the cost.

Read Also: Comparison Of Veranda Trim Vs Azek

Ease of installation: The simplest installation on our list, draft blockers require virtually no effort. Simply identify the source of the draft and lay down the draft stopper. If you decide on a DIY draft stopper, you’ll have to make one, but it’s a relatively simple project.

Effectiveness: If you want to increase energy efficiency and reduce energy costs, draft blockers can help you save. However, they’re not as effective as other methods that fall within the same price category.

My opinion: Draft stoppers work well as temporary or supplemental draft-blocking solutions. However, there are better and more effective alternatives if you’re seeking long-term strategies to keep your house warm.

Read Also: How to insulate your walls

Option 3: Hang Thermal Curtains

Curtains don’t just function as a decorative element to your room — they can also act as a first line of defense in helping to control your home’s temperature. Made of acrylic foam sandwiched between two or three layers of fabric, thermal curtains block air coming through the window treatments. This can help reduce the costs of your home’s heating and cooling, making them a great year-round solution.

Woman pushing window curtains to the side to look out

Pricing: Thermal curtains can be purchased for between $20 and $100, depending on size, material, and brand. Generally, you can find thermal curtains wherever regular curtains are sold, like big box stores or online.

Ease of installation: Thermal curtain installation requires very basic skills. You can easily install thermal curtains if you can operate a drill or screwdriver and use a level. The installation will be even simpler if you can talk someone into helping you.

Effectiveness: Thermal drapes can greatly reduce the amount of cold air entering your home and minimize heat loss. However, thermal curtains are only effective when they’re closed. If you want to insulate while allowing natural light into your home, there are better alternatives.

My opinion: While there are more effective methods for preventing cold air from entering through your windows, thermal curtains are an easy first step or additional accessory. Thermal drapes can be inexpensive, relatively easy to install, and enhance your home’s aesthetic, making them a well-rounded solution.

Option 4: Reinforce Your Weather Stripping

Old weather stripping can become worn down, dry, and brittle, which can lead to easy air infiltration. If the weather stripping around your windows is dated, replacing it can make a huge difference in draftiness.

woman replacing the weatherstripping on her windows

Pricing: The price of weather stripping varies depending on the size and type. Generally, you can get a roll for anywhere between $5 and $15. A 25-foot roll is more than enough to use on two windows (and you should have some to spare).

Ease of installation: Installing weather stripping is straightforward. Just peel off the adhesive backing and place it in the areas that need reinforcement. The only tool you need is a pair of scissors, making this a simple and affordable project.

Effectiveness: Weather stripping is a functional product. It can help seal cracks in your home and noticeably reduce your energy bills. Different kinds of weather stripping have varying levels of effectiveness. However, regardless of the type you install, you’ll quickly feel a difference.

My opinion: Installing weather stripping is an affordable and effective way to stop drafts and reduce energy consumption. One major benefit of weather stripping is that your windows remain operational, making it an optimal choice for those who want fresh air.

Read Also: Guide on Air-Sealing Your Home

Option 5: Installing Window Film

Transparent window film attaches to the interior of your windows on the outside edge of the frame. Window film is available in various sizes, though most often, you’ll need to cut the film to fit your windows. The plastic sheeting creates a dead-air pocket, inhibiting air and thermal infiltration, reducing utility bills and less draftiness.

man applying film to his windows for added insulation

Pricing: The price of window film will vary depending on its size, but generally, you can expect to spend $5 to $10 per window. Window insulation kits often come with double-sided tape and a cutter, but you may need to purchase these items separately.

Ease of installation: Installing plastic film is easy once you get the hang of it. The most difficult part of the process is cutting the film to size, but once you’ve done that, apply adhesive tape to the outside edge of the window and then put on the film. Afterward, apply gentle heat with a hairdryer — this bonds the film to the adhesive and shrinks it to form a tight seal.

Effectiveness: When installed properly, window film insulation is extremely effective. Essentially, it’s an additional pane on your window, making it a double-pane window that helps with heat retention while still allowing in sunlight.

My opinion: Window film is a reliable option to stop drafts and keep your home’s temperature. However, it renders your windows inoperable. If you live in a temperate climate, it may not be the best option if you need your windows to remain functional.

Which Insulation Method Is Best for Your Windows?

Caulking the gaps in your windows is the best method of adding insulation. You should see significant results, especially when combined with any of the other suggested methods. It’s also extremely cost-effective and easy to do. Temporary caulk can be removed during the warmer months. Keep in mind that exterior windows also require regular caulking to keep moisture and air out of your home.

When Should You Replace Your Windows for Improved Insulation?

While many of these methods are effective temporary solutions, you may want to consider replacing your windows. If your windows are nearing the end of their lifespan or they’re severely deteriorated, it is likely time to replace them. A temporary solution in this situation is only a stop-gap. If you’ve noticed major drafts or water leaks even though the window is fully caulked and weatherstripped, a replacement will also be the better long-term solution. In addition, if your home has single-pane windows, they likely have low insulation already and temporary solutions won’t do much. You’ll instead want to opt for double or triple-pane windows as replacements.

Whether you opt for a premium or a more affordable option, new windows will increase energy efficiency and save you money on your heating bills. If you need new windows, here are the three providers I recommend:

Frequently Asked Questions

What Can I Put on Windows To Keep the Cold Out?

You can effectively keep the cold out of your house by applying caulk to any gaps in your windows. Additionally, you can hang thermal curtains, apply weather stripping or window film, or use a draft stopper.


What Is the Cheapest Way To Insulate Windows for the Winter?

The least expensive and most effective way to insulate your windows for the winter is with caulk. For about $10 to $15, you can insulate any cracks in your windows and maximize energy savings.


Is Window Insulation Film Worth It?

Window insulation film works well and is worth the installation time and effort. Not only will your home be less drafty, but using film helps to conserve energy and lower your utility bills.


Does Adding Insulation to Windows Help Reduce Heating Costs?

Yes, adding insulation to your windows and sealing air leaks are some of the most cost-effective ways to reduce heating costs in your home. By completing both of these tasks, you could save up to 10% on your energy costs.


Article Update Log
6/6/2024
Reviewed for accuracy, cost data, industry best practices, and expert advice by Hilary Cairns.
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Dani Straughan

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Dani Straughan is a content producer for Today’s Homeowner from Durham, North Carolina, with an extensive writing background across multiple industries, ranging from coffee to automotive parts. Dani specializes in creating empathetic content that helps readers make informed decisions about home products and services. When they’re not writing about DIY projects and roof care, you will likely find Dani building custom handcrafted furniture or going on nature walks with friends.

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Hilary Cairns

Hilary Cairns is a writer with 12 years of professional writing experience. She has covered a diverse set of topics such as custom home building, plumbing, HVAC, energy efficiency, and others. A graduate of SUNY New Paltz with a bachelor's degree in English and a concentration in Creative Writing, she discovered her passion for helping businesses and organizations deliver impactful content that changed lives. Originally from New York, Hilary now calls Florida home (along with 2 cats). When not immersed in her writing work, she enjoys playing video games, reading Stephen King, and researching her (and her friends') genealogy.

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