Making Doors and Windows More Energy Efficient

When it comes to energy loss in homes, doors and windows are major contributors, accounting for up to 30% or more in some cases. Addressing these issues can bring your monthly energy bills down, reduce costly repairs to overworked HVAC systems, keep you more comfortable and contribute to a healthier environment. Let’s look at some ways people are making doors and windows more energy efficient. 

Maximizing Door Energy Efficiency 

• Weatherstripping: Exterior doorways typically have a flexible strip of material around their tops and sides called weatherstripping that helps seal gaps and prevent air flow in or out when the door is shut. If yours is old and worn, consider replacing it to keep things buttoned up—you can check with a flashlight to see if light leaks in around your door. Replacing old weatherstripping is relatively easy, and there are several types, including foam tape, V-strip and rubber/vinyl gaskets. 
• Door Sweeps and Bottom Seals: Sealing the underside of your door is important, too, which is why doors generally include a sweep or bottom seal. But these can become worn out over time, so it’s a good idea to evaluate yours. Brush-style sweeps are great for uneven floors, and rubber/vinyl sweeps are praised for their effectiveness and durability. Both types come attached to a metal or wooden frame that can be glued or screwed to the bottom of your door—be sure to measure the width of your door before purchasing. 
• Insulated Doors: Most exterior doors used in new construction these days are insulated. But there are still millions of homes in the U.S. with just solid wood or even hollow-core doors, which are both less energy efficient than today’s insulated fiberglass or steel exterior doors. If you’re a homeowner with old, drafty exterior doors, consider upgrading them to models with higher thermal resistance—some even come with a government Energy Star certification. 
• Storm Doors: Adding storm doors to the exterior of your home can serve as an added barrier against extreme temperatures and air leakage, as well. These also serve to protect your main door from the elements, and some models have screens that can be used seasonally to let fresh air in when the weather is nice. Choose one with a tight seal and insulated core for the most benefit. 
• Improper Fit: Exterior doors that weren’t installed correctly—or that have shifted over time as your house settles—are likely to have air leaks around the frame. Door frames need to be square and plumb, meaning you should have an even gap all the way around—new weatherstripping will do little good when your door is wonky. If you’re handy, you can correct these issues by removing the door trim and adjusting the screws and shims that keep the frame in position—use a level to check for accuracy. Some door frames can be tricky, so consider hiring a professional if needed. 
• Glass Inserts: If your exterior doors have thin glass panels, these can present issues, as well. Consider upgrading these door windows with double- or triple-pane glass filled with argon gas. Or choose glass that has a low-E coating that reflects heat. Insulating window film is a low-cost option, too, as this can be applied to your existing glass panels. 
• Door Curtain and Draft Stoppers: An easy option for renters and homeowners, thermal door curtains provide an insulating layer to help minimize heat transfer. Draft stoppers—also called draft snakes—are fabric tubes you can place at the base of your door to prevent air flow. Both are great for temporary or seasonal use. 

Optimizing Window Energy Savings 

• Air Leaks: As with doors, leaky windows are a common source of energy loss in homes. To check for leaks, try using a candle flame or the smoke from a stick of incense to detect air movement around your windows and frames. If you’ve got leaks, you can use latex caulk inside to seal stationary joints—where the window unit meets the wall. Outside, make sure to use silicone caulk, as it’s more resistant to weather. For moveable parts on your windows, try weatherstripping—either foam tape, V-strip or felt. 
• Window Film: As a lower-cost alternative to replacing inefficient windows, some homeowners choose to apply window film, of which there are several types. Low-E film reflects heat and UV rays. Tinted film reduces solar gain and glare, and there are even brands that also provide shatter resistance, improving your home security. You can perform this upgrade yourself with kits online or at home improvement stores, or hire a professional. 
• New Windows: On the more expensive side of energy efficiency, homeowners can also invest in brand new windows, though the work is sometimes more than the average DIYer will want to perform. But no matter how you tackle such a project, replacing old single-pane windows with modern versions designed to reduce heat transfer will cut your energy costs—and potentially boost your property value. Double- or-triple-pane windows filled with argon are two of the best choices, though there are also windows available that come with Low-E coatings that keep unwanted heat out in the summer and reduce heat transfer outside when it’s cold. When you’re shopping for new windows—or going over options with a contractor—look for labels such as NFRC (U-factor rating) and SHGC (heat gain rating). 
• Storm Windows: Like the storm doors mentioned above, storm windows can add an extra layer of insulation and air sealing. And there are versions available for the outside of your home, which are more permanent, or the inside, which are easier to install and remove seasonally. Modern versions of both exterior and interior storm windows often include tight seals and Low-E coatings. Both are a lower-cost alternative to replacing windows. 
• Insulating Treatments: Window coverings can help increase energy efficiency in your home, as well—and there are lots of options that work great for homeowners or renters. A few include cellular “honeycomb” shades that trap air as an insulator, thermal curtains that block drafts and radiant heat, and reflective blinds that bounce heat away when it’s hot outside. 

Efficiency Rebates and Credits 

You can also sometimes offset the cost of door and window replacement (and other upgrades) through various rebate and tax credit programs aimed at increasing efficiency in American homes. The Energy Efficient Home Improvement Credit through the IRS, as well as other state and local rebates or those offered through your local utility company, may be worth checking into. As of 2025, the IRS program is still an option, if you qualify, though proposed legislative cuts could end the federal program in 2026.