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White thermal curtains pulled aside to reveal modern windows in a contemporary living room with two couches and tables
February 8, 2024

Best Thermal Curtains for Insulation

Window treatments have long been used for insulation, whether to keep spaces cool or warm. The right window treatments can even help lower your energy bills. In terms of insulation, thermal curtains are one of the best solutions, thanks to their thick fabric that traps hot or cold air at your window for a more temperate, comfortable interior temperature.

Thermal, or insulated curtains come in a variety of styles and materials, so how do you know which is right for your space? First, learn what exactly thermal curtains are and how they work. Then, explore product options and get tips on how to make the right selections for the best energy efficiency. Finally, learn how to order your drapery and get tips on installation and maintenance.

What Are Thermal Curtains?

Thermal curtains are drapery panels made from high-quality, thicker fabrics, like wool, cotton or synthetic fabrics, and feature privacy or blackout lining as well as interlining. Interlining is a cotton flannel insert between the drape fabric and lining that adds extra insulation to your thermal drapes.

Why Choose Thermal Curtains?

Bedroom with king size bed and floor-to-ceiling window curtains with text listing the features of thermal curtains

Thermal curtains offer several unique benefits beyond excellent insulation, including:

  • Great privacy for peace of mind, thanks to the thicker fabric, and sometimes added lining as well, that blocks the view into your home.
  • Room darkening for better sleep, so you wake up feeling refreshed, especially when you choose blackout lining for your already thick drapes.
  • Sound insulation for a more tranquil space, since the thicker fabric and added lining absorbs sound.

Do Thermal Curtains Really Work?

In short, yes. Thermal curtains trap cold or hot air at your window which keeps it from circulating in your room, so your living area stays comfortable. The level of efficiency of your thermal curtains will depend on the fabric and lining chosen, as well as how you hang your curtains over the window to block the most airflow.

What Is the Difference Between Thermal & Insulated Curtains?

Both can be used to refer to curtains that help to trap cold air at your window and prevent a draft in your home. However, sometimes “insulated” can be used in terms of sound insulation, but it should be noted that thermal curtains also will naturally help with sound absorption thanks to the thickness of the material.

How to Order the Best Thermal Curtains

Walnut-colored thermal curtains hanging in a dining room with a vintage wooden table in the foreground with two candles lit

Now that you know what thermal curtains are and how they work, learn how to order the best thermal curtains for your space. Ordering thermal curtains is the same as ordering any type of curtain, but these steps specifically list the best selections to make for insulated drapes. However, there are other many options to choose from as well, depending on your preference.

Step 1. Learn Best Practices for Hanging Drapes

Ordering will require measuring your window so you can select the right size premade panels, or for custom thermal curtains, you’ll be able to order panels that perfectly fit your measurements. For custom drapery especially, measuring appropriately will ensure your drapes accentuate your window and your room as a whole. To measure appropriately, it’s important to understand the best practice for hanging drapery.

These best practices will help guide your actual measurements:

An illustration shows how to hang thermal curtains in terms of a window's height and width with measurement suggestions

hang your drapery high & wide

Hanging your drapery panels at least 12 inches beyond the window frame on either side and a little more than halfway between the top of the window frame and ceiling creates the illusion that your window is larger, and your ceiling is taller.

Plus, the tall, wide panels are more effective at fully trapping outside air at your window for the best insulation.

Step 2. Measure for Ordering Length & Width

Now that you know the best practices for hanging drapery, learn how to measure your window for the ordering length and width of your insulated curtains.

Measuring Width

Measure the width your curtain rod will extend, making sure it extends about 12 inches beyond the window frame on either side. When ordering from The Shade Store, this is your ordering width.

If ordering custom Drapery elsewhere, you may need to multiply the width of your curtain rod by 1.5 or 2 so your drapery panels are wide enough to create a lush, full look when pulled across your window. At The Shade Store, we do this math for you and take your chosen drapery fabric and lining into account to give you the optimal fullness

An illustration shows how to hang thermal curtains in terms of width with measurement and stack and fullness suggestions
An illustration shows how to hang thermal curtains in terms of length with measurement and float suggestions

measuring length

To measure the length, measure the distance from the rod or track system to the floor.

You have three main lengths to choose from. For the best insulating effect and functionality, opt for break-length curtains which just kiss the floor.

For break-length drapes, add 1 to 2 inches to the length you measured between the hardware and floor.

Other drapery length options include:

Float-length drapery: Measure from your rod to about ½ inch off the floor.

Puddle-length: Add 3 to 6 inches to your curtain’s float length.

Do Thermal Curtains Need to Touch the Floor?

For the best insulation, yes, your thermal curtains should touch the floor. This is especially important for cold climates, since cold air is heavier than warm air, it will naturally drop to the floor, so floor-length curtains will more effectively trap cold air at your window. 

Leave It to the Pros

Prefer to let professionals handle your measuring? When you choose custom Drapery from The Shade Store, you enjoy free measurement services from our team of professionals.

Step 3. Select Your Pleat Style & Hardware

Beige-sand-colored curtains are pulled apart to reveal trees and a pool while inside light falls on a crisply made bed

For thermal curtains to work the most efficiently, it’s important to have good functionality — and functionality depends on your pleat style and hardware selection. Your selections should allow you to easily close your drapery entirely over your window for the best insulation, but also allow you to open the drapery to take advantage of pleasant weather. For instance, you’ll also likely want to adjust them on sunny days during the winter to let the warm light in to warm your home or on summer nights to let in a cool breeze.

Learn more about your functional pleat style and hardware options to find the right fit for your insulated curtains.

Functional Pleat Styles

Functional pleat styles are those that are easily adjusted without any extra effort. Ideally, you’ll want pleat styles that are compatible with track system hardware, which allows the panels to glide effortlessly on the track for the easiest functionality.

Functional pleat styles include:

Interested in Other Pleat Styles?

If you’re looking for decorative drapery or stationary panels to be paired with another insulating window treatment, you have several more options.


For the best pleat style for insulation, we recommend Ripple Fold, Tailored Pleat or Pinch Pleat Drapery. These offer nice fullness (the thickness of the drapery when it’s pulled over your window), especially when paired with a thick fabric and lining. Cubicle Drapery, while easy in terms of functionality, is not nearly as full, so will provide slightly less insulation for your window.

Functional Hardware

Drapery hardware comes in two main categories: track systems and rod and rings hardware. In terms of functionality, track systems are your best bet. Learn more about each to solidify your choice.

Close-up of three Madison track systems with various finials and colors, including black, gold and bronze

Track Systems

They feature carriers to which your drape panels are attached so the panels glide easily back and forth on the track. Track systems come standard with a baton you can use to move the drape panels across the track without touching the fabric.

Close-up of four wrought iron drapery hardware sets made up of rods and rings stacked one on top of the other

Rod & Rings Hardware

Rod and rings hardware has rings on a rod, which can be a bit more difficult to adjust, especially on wider windows where brackets may impede movement. However, on most average-sized windows where brackets won’t be an issue, rod and rings systems are a fine option.

Product shot of a smart home device, a remote control and a wireless link used to link a motorized system to a smart device

Want Effortless Ease? Go for Motorization

For truly effortless ease of use, choose a motorized track system which allows you to adjust your drapery with the touch of a button on a remote. Some systems, like our proprietary motors, can also be paired with an app on your smartphone or tablet, or even with a smart home device like Amazon Alexa, so you can control it with the sound of your voice.  


For the easiest functionality, we highly recommend a manual track system or a motorized track for your insulated curtains. Track systems are so easy to use and allow you to adjust your drapery as needed throughout the day and night to optimize your interior climate. Motorized track systems can even be automated with a timer to open and close according to your preferences.

Step 4. Select Your Drapery Fabric

The best thermal curtains are made with thick, absorptive fabrics like wool, cotton, heavy linens or synthetic blends. Choosing between these fabrics is mostly a matter of preference, although there are a couple things to keep in mind:

Product shot of fabric for thermal curtains focusing on the thick, absorptive fabrics like wool with natural fibers

Natural Fabrics

Natural fibers like wool, cotton, and linen, may be prone to stretching or wrinkling. These imperfections are often seen as desirable characteristics that showcase the beauty of the natural material and add charm to its appearance.

Product shot of fabric for thermal curtains, focusing on synthetic fabrics in multiple colors such as blue, white and grey

Synthetic Fabrics

If you prefer a more pristine, unaffected looks, opt for synthetics like Sunbrella or natural and synthetic blends. These materials are more resistant to staining, stretching, wrinkling and more, making them ideal for more active rooms like kitchens, living rooms, or kids’ rooms.

Best Fabrics to Choose for Insulation

Explore this selection of some of the best fabrics to choose for insulated curtains.

Product shot of Holland & Sherry wool flannel in various colors stacked one on top of another on a right angle

Holland & Sherry, Wool Flannel

A 100% wool fabric, Wool Flannel is thick and luxurious with a slightly brushed finish for a soft touch.

Product shot of a fabric called Aberdeen, which is a wool and synthetic blend featuring a plaid pattern


A wool and synthetic blend featuring a luxe plaid pattern with an authentic woven texture.

Product shot of a Nate Berkus fabric in claude stripe, featuring a soft, inviting blend of linen, wool and synthetic fibers

Nate Berkus,
Claude Stripe

A soft, inviting blend of linen, wool and synthetic fibers, with a luxe boucle stipe for visual and tactile texture.

A product shot of a Sunbrella material made of 100% Acrylic and featuring a heavyweight linen look with excellent durability


Made of 100% Sunbrella Acrylic, Alma features a heavyweight linen look with excellent durability.


Wools and wool blends are really your best bet for insulation against the heat and cold. Wool is a unique material in that it is crimped, which means it creates tiny air pockets that trap air in the fabric and slow the transfer of heat. This keeps your home warmer in the winter and cooler in the summer.

Step 5: Add Lining

Two windows feature thermal curtains in a tailored pleat style beside a relaxing area with two couches facing one another

While lining is typically an optional choice for ordering custom drapery, for the best thermal curtains, it’s essential to pair your thick fabric with drapery lining.

Interlining with blackout lining will give you the best insulation against both the heat and cold, thanks to the blackout lining’s ability to block the hot sun and the interlining’s cold-blocking abilities. However, you can also pair interlining with privacy lining for a lighter look for your drapery and the potential for some soft light to filter through the fabric.


Interlining is a must for thermal curtains. Whether you pair it with privacy or blackout lining is up to you, but the cotton flannel insert is essential for giving you the best insulating properties for your drapery.

Installation & Maintenance: A Brief Overview

If you’re considering a DIY installation for your thermal curtains, get an overview of the steps so you can gauge your comfort level with the job.

Installing Insulated Curtains

Installing your drapery will vary based on the type of hardware you’ve chosen, but in general, your steps will include:

A professional installer standing on a step ladder smiles as he marks where to place a bracket beside a window

Step 1: Gather tools. You’ll likely need a stepladder, pencil, tape measure, level, drill and screwdriver, but check your drapery’s specific install instructions for an exact list.  

Step 2: Measure bracket placement based on your hardware’s width. Be sure to check your drapery hardware install guide to ensure proper spacing of brackets.

Step 3: Install the brackets with the correct tools as indicated in the installation guide for your drapery hardware. 

Step 4: Mount the rod or track system and hang your drape panels.  


The exact care your insulated curtains will require will depend on the fabric, however, for all fabrics, there are a few best practices:

  • Use a low-suction handheld vacuum to regularly remove dust and dirt from your drapes.
  • For stains, we recommend contacting a professional window treatment cleaning specialist who will likely be able to treat your drapery onsite, without taking it down. If you can’t find a window treatment cleaning specialist, consider taking in a swatch of the material to your local dry cleaner to discuss your options.

Make Your Final Selections in a Showroom

With a better understanding of thermal curtains under your belt, you’re ready to consider your final selections and place your order. Visit a local showroom where you’ll find interactive product displays, swatches of all your fabric options, and more. Plus, you’ll meet our expert Design Consultants who can answer all your questions and guide you toward the right selections to optimize your insulated curtains while giving you a look you love.

A round white table with cream chairs sits in a custom window treatment showroom with drapery, shades and blinds displayed.


Visit your local showroom for interactive displays of all our products, 1,200+ premium material swatches and helpful Design Consultants ready to assist you.