Energy-Efficient Windows

Energy-efficient windows prevent heated or cooled air from escaping your home, allowing HVAC systems to operate efficiently. They reduce your energy bills, a significant expense for most homeowners, and increase the comfort of your home year-round.

Many factors affect the efficiency of your window. Some of these include the window style, frame material and glass.

Frame Material

The type of window frame you choose has a large impact on the performance of your windows. Energy efficient frames are usually made of vinyl, fiberglass, or composites. They reduce the transfer of heat, allowing your heating and cooling systems to work more efficiently. This can help reduce your energy bill.

Energy efficient windows also block out unwanted noise from outside. This can be especially helpful if you live in an urban area. Many people who are considering new windows are often worried about the cost, however there are many ways to cut costs on this home improvement project. Many local governments offer rebates and incentives for energy efficiency improvements.

The type of glass used in an Energy-efficient window is also important, as it can affect how much heat is lost through the window. Energy-efficient double pane windows use multiple sheets of glass that are sandwiched together with spacers. This creates air pockets that insulate the window, keeping the interior warm in winter and cool in summer.


A window’s glass plays a critical role in its energy efficiency. It allows in the sun’s warming rays in winter and helps keep them out in summer, while maintaining a comfortable temperature throughout your home.

A standard double-glazed unit lets up to 75 percent of the sun’s heat into your home. ENERGY STAR windows with low-emissivity (low-e) coatings can reduce this by as much as 24%.

In addition to a low-e coating, ENERGY STAR windows contain argon gas in their insulated units, further reducing the amount of heat that passes through them. This reduces your heating and cooling bills and reduces the amount of greenhouse gases in your home’s atmosphere.

The best way to reduce air leakage through your windows is with a hinged-sash style such as casement or awning windows, which create a tighter seal when they are closed. This can shave up to 30% off your energy bills. You can also add an Intercept warm-edge spacer system to your new windows, which insulates the edges of the insulated window and tacks on another 5% in savings.


Weather stripping is a series of strips that stick to the edges of your door or window frame. When properly installed, they prevent air leaks and water from getting in. It also helps keep the inside of your home conditioned, and saves energy on heating and cooling.

Felt is a common DIY weather stripping material that’s inexpensive, but doesn’t last long and can become brittle in high moisture areas. Foam tape is a slightly more advanced option that’s similar to felt, except it’s made from open or closed-cell foam with an adhesive backing.

The best way to test your doors and windows for needing weather stripping is at night. Have one person go outside and hold a flashlight around the perimeters of your door or window. If you can see light shining through, your seal isn’t good enough and you need to add more weather stripping.


Over time, gaps and cracks can develop around windows. These can cause heated or cooled air to escape and raise your energy bills. Window sealing creates an additional barrier that prevents this from occurring and helps your home to stay comfortable year-round.

When choosing new windows, be sure to look for ENERGY STAR certification. These windows have been independently tested to ensure that they meet NFRC performance requirements. JELD-WEN is an industry leader in window manufacturing and offers several lines of ENERGY STAR certified products.

In colder climates, select a window with a low U-factor to reduce heat loss. In warmer climates, opt for a window with a low SHGC to minimize solar heat gain. In addition, choose windows with low VOCs to minimize indoor air quality issues. Make sure to ask professionals about their product offerings and to compare quotes carefully. Make sure to obtain documented estimates that include labor and materials. This can help you balance your goals with the cost of your window replacement project.