About 30% of a home’s heating energy is lost through the windows, according to the U.S. Department of Energy. But with the right windows and long-term care, you can cut back on air leakage, reduce unnecessary heating and cooling and lower your utility bills.
Window replacements are pricey, however, costing about $650 per window on average, according to HomeAdvisor. The cost can range from $300 to $1,000 per window depending on material, size and features, and those that are energy-efficient tend to be more expensive. While you will likely see reduced utility bills with these, don’t expect to recoup the value quickly. However, new windows can increase your quality of life by keeping rooms the right temperature, reducing outside noise and improving curb appeal.
Here are the details to consider when you begin shopping for energy-efficient windows:
- Window type.
- Panes of glass.
- Spacers and filling.
When shopping for windows, look for certified Energy Star products or those with an optimal rating from the National Fenestration Rating Council, which has a voluntary program for testing and certifying windows, doors and skylights. NFRC ratings are incorporated into Energy Star certifications; Energy Star is a program run by the U.S. Environmental Protection Agency.
With NFRC ratings, the lower the number, the more energy-efficient the product. The key ratings are:
- U-factor. The amount of non-solar heat that can transfer from outside to inside.
- Solar heat gain coefficient. The amount of solar radiation that can transfer from outside to inside.
- Air leakage. The amount of air that flows through the window, measured by cubic feet per minute of air transfer.
- Visible transmittance. The amount of visible light transmitted from outside to inside.
"These values vary depending on where you are, and homeowners should be aware of the requirements in their particular climate zone," Troy Rubenzer, product manager for window replacement company Renewal by Andersen, wrote in an email. Energy Star has four established climate zones throughout the U.S., based on the seasonal temperature and hours of sunlight.
Fortunately, you won’t be hard-pressed to find Energy Star-certified windows when you start shopping; it’s just a matter of selecting the right window and features for your home. “It’s almost impossible to not find an Energy Star-rated window. It’s counterintuitive (for manufacturers) to not make that,” says Jeff Ludy, founder and owner of Houston Window Experts. Just like with household appliances that carry the Energy Star certification, the Energy Star logo will be prominent in any product description that meets requirements, along with the individual NFRC ratings.
When choosing a type of window for your home, consider whether it is more or less likely to leak air. Here are the most common types of windows:
- Single- or double-hung. These windows have an upper and lower sash, or movable portion of the window. A single-hung window can only be opened by sliding the bottom sash up, while both sashes can move up or down.
- Sliding. A window with sashes that open by sliding horizontally.
- Casement. A hinged window that opens from the side.
- Awning. A hinged window that opens from the bottom.
- Hopper. A hinged window that opens from the top.
- Fixed. A window that does not open. These are rare in residential homes, as building code requires the ability to open windows for air or as a means of egress in case of a fire.
The double-hung window is one of the most popular types of windows on houses today. But according to the Department of Energy, it’s also more likely to leak air than a casement, awning or hopper window. Sliding windows also have higher leakage rates, as the Department of Energy notes in its breakdown of window types.
However, hinged windows such as casement, awning and hopper windows may not offer the look or functionality you want. They require more space around the window to allow them to open inward and may not open wide enough to welcome a breeze.
The material of the frame you choose is an important consideration when you're looking to insulate your windows.
Vinyl and fiberglass offer substantial energy efficiency as long as they are properly insulated. Wood or composite frames can also insulate well, but their performance is not as high as fiberglass or vinyl that has insulation included. Wood frames also require more maintenance. Metal frames have the lowest performance quality regarding energy efficiency.
Panes of Glass
If you live in an old house with original windows, there’s a good chance they have a single pane of glass, which does not effectively stop outdoor temperatures from affecting your inside climate control. Windows today are often double- or triple-paned, with space in between, which cuts down on the loss of thermal energy.
Energy Star-rated windows today have three coats of low-emissivity, or low-e, glazing. This coating reduces the amount of sunlight that comes through the windows. Ludy points out that in some cases, a homeowner with a house that receives little direct sunlight might want fewer coats of low-e glazing to keep the house from feeling even darker.
Spacers and Filling
Between your panes of glass, there are spacers to help keep the glass in place, and they also provide an additional level of protection to keep windows airtight and moisture-resistant. Spacers come in different shapes and materials, such as stainless steel, aluminum and silicone foam, and with sealants to keep them effective.
You may also have the space between panes of glass filled with gas to cut down on heat transfer. The Department of Energy notes that krypton and argon are the two most common gases used – krypton for space around one-quarter inch, and argon for wider spaces.
In addition to the window itself, consider things that can keep your windows energy-efficient:
- Proper installation.
- Weatherstripping and caulk.
- Window treatments.
Not only do you need to find the right energy-efficient windows for your house, but you need an installer who is going to do the job right. As Ludy says: “A great window with a bad installer is a bad window.”
Be wary of installers that are willing to make an estimate without visiting your property, taking measurements and learning about the structure of your home, he says. Wall thickness and the exterior material of your house play a role in what type of window fits best.
Like with any contractor, you should have multiple service providers come to your house and provide an estimate. While price will certainly play a role in your final decision, also factor in whether the product offers the level of energy efficiency you want and meets other needs.
If you're offered a lifetime warranty on your new windows, be sure to read the fine print. Rubenzer says some warranties only cover the glass or frame, or the warranty won't transfer to the new owner if you sell the house.
The company you choose should also have a solid history of doing business. "A lifetime warranty does you no good if the company it comes from is here today and gone tomorrow," Rubenzer says.
Weatherstripping and Caulk
Over time, your house settles, and windows and doors may not remain as airtight as they were upon installation. Check annually around your windows for any leaks that might be letting cool air in during winter and out in the summer.
On the exterior of the window frame, you can use caulk to seal edges where air can get in. If air is leaking between the window and frame, you can use weatherstripping, which is a padded strip with adhesive on one side, to provide more insulation.
Blinds, covers and curtains aren’t just for privacy or aesthetics. They can also offer additional insulation to reduce heating or cooling loss through windows. If a room has a tendency to get hot due to direct sunlight on summer afternoons, close the blinds or draw the curtains to avoid having to crank the air conditioning higher.
In the winter, be sure to open blinds and curtains when the sun is out to help reduce the amount of work your furnace has to do.
For more information on energy-efficient windows, the Department of Energy has an in-depth guide that breaks down all the details of replacing your windows.
A renovation project for each season
Homeownership comes with a never-ending list of home improvement projects, and being able to time them right can be tricky. Ultimately, the best time for a home improvement project is when you have the time. But if you’re eager to plan projects to set yourself up for success, consider which season has the right weather patterns, minimizes future maintenance issues and makes it easiest to hire professionals. Read on for the best time of year for 12 home improvement projects.Interior paint
Best time of year: Winter
The benefit of painting inside is that you have air conditioning and heating. “We paint interiors all year-round because of that climate control,” says Tina Nokes, co-owner of Five Star Painting in Loudoun County, Virginia, which is a part of Neighborly, a network of home service providers. Your biggest concern when it comes to a quality indoor paint job is humidity – so if you’re in the middle of a humid summer, it’ll take longer for a room to dry and it will dry unevenly. If you’re worried about humidity levels inside, paint your interior rooms during the winter, when the air is driest.Electrical updates
(Paul Bradbury/Getty Images)
Best time of year: Winter
Electrical work can happen just about any time of year, unless it’s during rain or a thunderstorm, for obvious safety reasons, explains Dennis Burke, owner of Mr. Electric of Southeast New Hampshire, which is also a Neighborly company. What truly makes winter a winner for electrical updates is that you’ll be avoiding the bulk of competing homeowners. Burke says late spring and early summer see a big influx of requests from clients, as well as late summer as people go on vacation. “Labor Day to Thanksgiving is also really busy,” he says.Building a deck
Building a deck
Best time of year: Winter
An outdoor project like a backyard deck seems like a natural undertaking for summer, but it’s actually just the opposite. Deck builders and contractors report that pressure-treated wood, which is best for building a deck, stabilizes best when humidity is low. Additionally, the increased sun exposure in summer can cause the surface of a deck to crack, and cloudier winter days help avoid early damage. If you live in a particularly cold climate, aim for early winter to avoid the bulk of snowfall and temperatures that are too cold for contractors to work outside.Full-room remodel
Best time of year: Winter or spring
Remodeling or updating a well-loved room in your home can happen any time of year, but it’s best to be proactive and avoid higher labor costs or jampacked contractor schedules during the summer months. HomeAdvisor reports that July is the busiest month for bathroom remodel requests, with 48 percent of homeowners indicating they’re ready to hire and start work immediately. Avoid the rush by scheduling your remodel earlier in the year.Cleaning out gutters
Cleaning out gutters
Best time of year: Early spring and fall
The gutters along your roofline collect leaves, twigs and other debris over time. When they get too full, the drains can clog and cause water to sit along the edges of the roof and get inside the house or continue to weigh down the gutters. Avoid any problems by cleaning out your gutters in the fall, when leaves are most likely to make their way in, and again in early spring so the path for water is clear before April showers roll in. If you're not comfortable on a ladder or you have a high roofline, consider hiring professional help that will take proper safety precautions.New floors
Best time of year: Spring or fall
The best time to install wood flooring is during parts of the year with the least extreme conditions. In spring and fall, you'll avoid peak humidity and dry air, both of which can cause problems like bowing and warped wood or cracking in too-dry conditions. Plus, you can open windows to ventilate the smell of wood stain or carpet adhesive, and you’re least likely to have the heat or air cranking in spring and fall.Updating a deck or fence
Updating a deck or fence
Best time of year: Spring, summer or fall
The wood on a deck may fare better in winter, but staining a deck or painting a fence often requires additional weather consideration. “Decks and fences are a little more finicky (than painting a house exterior). We need it to be even warmer, around 40 to 50 degrees,” Nokes says. A good deck staining or painting company will recommend a timeline specific to temperatures where you live to avoid an incomplete, delayed or flawed project.Exterior paint
Best time of year: Late spring, summer, early fall
New paint will freshen up the look of your exterior walls, and painting is a doable project for a decent chunk of the year. Temperatures have to stay above 35 degrees for exterior painting, so in the early days of spring and late days of fall, weather-dependent work may be delayed if temperatures drop. For this reason, Nokes keeps clients on a watch list: “If we get a warm snap, I’ll call them right away,” she says.Home addition
Best time of year: Late spring, summer, early fall
For outdoor work, it’s best to avoid the seasons that will bring inclement weather and delay the project. Plan for the project to begin after the chance of snow in your region has passed, and shoot for a completion date before the frost returns in the fall to reduce the chances of delays. But be sure to schedule all professionals well in advance. In fact, Burke says a month to two months’ advance notice is often needed for electricians to complete an estimate, plan a contract and schedule work.Roof repair and replacement
Roof repair and replacement
Best time of year: Summer, early fall
It’s a given that you don’t want people working on your roof in icy or wet conditions. As a result, the best time of year for roof repair or replacement is also when the professionals are busiest. Be sure to plan roof replacement a month or two in advance to avoid having to wait with possible leaks causing damage to the inside of your home.HVAC care
Best time of year: Early fall
Any repairs to your heating, ventilation and air conditioning system should be done as soon as you notice an issue, but if you’re planning to do routine maintenance, schedule a professional long before you’ll need to turn on the heat. That way, any potential problems that could leave you without heat are found and fixed before the first cold nights of the season. The same goes for air conditioning in the late spring and summer.New appliances
Best time of year: Fall
Consumers can expect everything from washing machines and oven ranges to refrigerators to sport discounts leading up to the holidays. Even if you’re not updating your kitchen until May (and your home can accommodate an extra oven or fridge for five months), keep an eye out for deals. Stores that sell appliances like Sears, Lowe’s and Home Depot are known to regularly offer holiday weekend deals.Read More
She has appeared in media interviews across the U.S. including National Public Radio, WTOP (Washington, D.C.) and KOH (Reno, Nevada) and various print publications, as well as having served on panels discussing real estate development, city planning policy and homebuilding.
Previously, she served as a researcher of commercial real estate transactions and information, and is currently a member of the National Association of Real Estate Editors. Thorsby studied Political Science at the University of Michigan, where she also served as a news reporter and editor for the student newspaper The Michigan Daily. Follow her on Twitter or write to her at firstname.lastname@example.org.