What to Know About Thermal Drapes

Updated: Aug. 25, 2023

When it's time to winterize your home, thermal drapes are a cost- and energy-efficient way to take off the chill.

Windows can be one of the biggest trouble spots when it comes to heat loss in your home. They allow precious warmth to escape outside and permit frosty air to seep indoors. Thermal drapes not only keep your family warm and toasty throughout long, dark winters, they can also save you hundreds of dollars on your heating bill. Here’s what you need to know about thermal drapes.

What Are Thermal Drapes?

Thermal drapes are specialized curtains that act as the first defense against drafts and the indoor/outdoor heat exchange around windows. Constructed of two, three or four layers of material, they’re designed to inhibit the amount of heat that passes through windows and glass-paned doors. Thermal drapes function as a buffer, forming a protective layer that insulates you from the cold.

Do Thermal Drapes Work?

Yes. According to the U.S. Department of Energy, energy-efficient window coverings can significantly reduce the amount of heat that travels through windows. It’s estimated that as much 30 percent of a home’s energy can escape this way! Thermal drapes work by creating a barrier between the panes of glass and your home’s interior.

Typically, thermal drapes are made of several layers of fabric: decorative, heat-blocking foam, non-breathable/vapor-stopping and sometimes reflective film. Together, these lined curtains trap the heat in and block the cold out.

When to Use Thermal Drapes

If you live in an area that experiences frigid winters, you can greatly benefit from investing in thermal drapes. For homeowners who are plagued with drafty windows, thermal curtains are especially important in giving you relief from high fuel costs as they help create a comfortable environment for you and your family.

Pro Tip: Check the R-Value, a measurement of a material’s ability to resist heat flow from one side to the other. The higher the number, the better the insulation.

Thermal Drape Types and Styles

Ready-made or custom (you can make them yourself), thermal drapes work from the inside to insulate your home. Mostly they’re constructed of thick, indoor-facing decorative cotton, wool or polyester material, followed by a layer of acrylic foam and a breathable layer that stops condensation and moisture from forming.

Thermal drapes can be found in various styles to compliment your décor. They can be hung through rods, on rings, by hooks or through grommets. A simple do-it-yourself solution is to hang two draperies together to create an air space that helps maintain the room’s temperature.

Pro Tip: Don’t confuse thermal drapes with solar curtains, which are designed to block out the heat in summer.

How to Install Thermal Drapes

Before buying curtains, measure your windows and make sure there’s plenty of material to extend out on either side and below. Don’t forget to add extra length so the drapery will extend onto the floor (so cold air can’t come in underneath), and make sure the drapes overlap in the center.

Hang the curtain close to the ceiling and as tightly as possible to the windows for the best insulation performance possible. When deciding which windows to cover, give priority to the north-facing side of your home.

Pro Tip: Using hook-and-loop fasteners or magnetic tape to attach the drapes to the wall helps avoid leaky gaps.