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Broken window panes can cause a variety of problems including air leakage and condensation build-up. (By Marin Blair)

By Marin Blair

Are your windows keeping your home as energy-efficient as possible? Sierra Club Green Home helps you check your windows and decide if you need to repair, retrofit, or replace.

Studies conducted by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) show that windows, depending on their performance, can account for 25-30% of the total heating and cooling energy use in a home. Replacing windows just to save energy generally isn’t cost effective due to high unit and installation costs. However, when windows are old, worn out or broken, it can definitely be cost effective in the long run to replace them with the most appropriate units for your home based on energy efficiency, solar exposure, usability and aesthetics.

Window basics

When learning about your options when it comes to windows it is important to start by doing a little research. Since there a large variety of window products are being offered on the market today, start by learning some of the most critical window assembly parts. A diagram of a standard window is shown below:

• U-Value is a measurement of the flow of heat through a material. The lower the U-value, the better insulating ability of a window assembly.
• Solar Heat Gain Coefficient (SHGC) is a term describing the percent of heat gain through the glass from solar radiation. Measured at a value between 0 and 1, the lower the SHGC the less solar heat the window transmits.
• Visible Transmittance is the property pertaining to the amount of light that is able to pass through a window.
• Condensation Resistance measures how well a window assembly resists the accumulation of moisture. Scored from 0 to 100, the higher the value the lower the susceptibility of water build-up.
• Air Leakage is the rate at which air is able to pass through different parts of a window. The lower the air leakage value, the less air leakage a particular window will experience.

Function and performance

Windows serve several purposes: to protect the home from the elements, to provide daylight and vision, to support occupant comfort, and to allow for natural ventilation. When windows perform poorly a variety of problems can occur:

• Water intrusion causes interior damage such as condensation and mold;
• Air leakage causes drafty and uncomfortable conditions for occupants;
• Excessive solar heat gain causes the air conditioning system to be less effective in cooling the home, increasing energy costs; and
• Excessive heat loss causes the heating system to be less effective in keeping the house warm, increasing energy costs.

If you are experiencing any of these issues, it’s likely your windows need repair or replacement. There is one caveat to this however, on the topic of air leakage. Often people think that when they stand near a cold window it means the window is leaking air, which is not always the case. When the exterior temperature is significantly lower than the indoor temperature like in the case of deep winter weather, convective looping of air as it hits the cold glass surface of a window creates a drafty feeling when, in reality, it may not actually be leaking. If you feel your windows are drafty and they appear to be performing properly visually (i.e. no broken panes, damaged sills, or moisture build-up), hire an energy auditor to test them for air leakage before moving further towards the decision of replacing them altogether.

Options available

So you’ve decided your windows need some work. What’s next? Again, some fundamental education is necessary to understand the options available and to decide which may be the best choice for you both financially and from a performance standpoint. In general there are five major options for improving the performance of your windows:

• Repair or rehabilitate current windows. Usually the cheapest option available, this fix involves replacing broken window panes, stripping and repairing damage to window materials, caulking joints, adding sealant, and installing additional weatherstripping and insulation to limit heat loss. This option will save space in landfills, but likely have less of an impact on energy savings in the long run.
• Install interior or exterior storm windows. Storm units work by incorporating another assembly on either the inside or outside of a window. The cavity of air that is trapped between the two units improves the energy efficiency of the assembly because a closed volume of air has a higher thermal resistance than glass alone.
• Modify existing units by replacing sashes. For this option, the existing window frame needs to be in good condition or it will cause problems during installation. While it remains more cost effective to make these smaller substitutes rather than replacement the entire unit, sash retrofits do not address performance issues that occur between the wall and the original frame such as water intrusion or air leakage. It may also be more difficult to find the exact size sashes you need if your windows are of an older style.
• Insert window replacements into the existing frames. Again, it could be tricky to find the exact size window you need to adequately replace the old unit, and installation must be done extremely well to ensure performance problems aren’t worsened. If the frames are in good shape then by all means try and salvage them, but keep in mind the cost gap to full unit replacements is probably shrinking.
• Replace the entire windows with new units. This is clearly the most expensive option and must be completed by someone who knows what they’re doing. This option provides the best means to integrate a window into an existing wall assembly, because it allows the rough opening to be altered if needed. When the entire unit is replaced that opens up the ability to play with the aesthetics by incorporating different sizes, shapes, and types of windows. An added benefit is that the market is now saturated with a variety of products that boast high performance qualities. Use your knowledge of window characteristics to compare different units side by side. Although this option may save you the most money over time, it also produces the most waste when old windows are scrapped.

Once you have an idea of the route you want to take, contact a local retailer to view the types of units available and their respective costs. If you’ll be doing the fixes yourself, be sure to do some further research and use the many do-it-yourself guides out there to plan it out (making sure the source of information is legitimate). If you plan on getting the work done by a contractor, get at least three bids comparing a few different products so you can get the best bang for your buck.

For more technical information on the types of energy efficient windows available and see some selection recommendations, visit the Efficient Windows Collaborative.

An important note on lead

Homes built before 1979 may contain lead paint. Of these homes, window assemblies are often the most common place for lead dust disturbance as friction from opening and closing the units loosens lead dust particles that are harmful for human development, especially in children, when ingested or inhaled. If your home was built before 1979, be sure to test for lead paint first by calling your local public health department and inquire about lead testing (generally about $10-20 per test sample). If testing verifies your window assemblies contain lead paint, make sure the contractor doing any sort of refurbishing or replacement abides by proper lead abatement protocol.

Marin Blair is a home performance contractor and consultant based in Edina, MN.

For related article see:
Solar Window Film Blocks Heat and Prevents Fading

© 2012 SCGH LLC.

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EnergyGlass can be combined with security glass to withstand disasters like hurricanes, forced entry, bullets, bomb blasts and fires. (Ecstaticist, Flickr)

By Debra Atlas
January 8, 2012  

With the growing emphasis on alternative energy sources and solar power, rooftop solar arrays are springing up around the country. As useful and environmentally-friendly as photovoltaic panels are, they don’t exactly blend in aesthetically. What’s more, they can sometimes be difficult to integrate with other rooftop equipment, and can sustain damage from exposure to the elements.

Florida-based SAF-GLAS, which creates disaster-resistant and security-related glass products, recently introduced EnergyGlass at a solar seminar at GlassBuild America. This transparent glass incorporates inorganic nanoparticles into clear laminated glass. With its use of a proprietary polycarbonate interlayer and patented film, this turns a window into a 24-hour a day solar “farm.”

The first of its kind, EnergyGlass goes beyond the capabilities of traditional solar power panels, which depend on both placement and angling in direct sunlight. It’s able to collect light from natural, ambient and artificial light sources such as hotel or office lighting. Once collected, the light is transformed into electricity, then used or sent for storage to a backup battery system for power outages or other emergency situations.

Unlike other solar windows, EnergyGlass windows have no lines or mesh incorporated into them. You get a clear view of the outdoors, as with any standard window.

EnergyGlass can be fashioned to any size, shape or style and can be installed in a vertical or horizontal position. Each window is made of two clear glass panels with a solar laminate sandwiched between them, creating a single laminated solar pane. It can be tinted, insulated and can even incorporate Low E glass and other related products to create additional energy savings.

This glass has numerous other applications. By including additional laminating procedures, it can be used in combination with security glass to meet hurricane, typhoon, tornado, forced entry, bullet resistant, bomb blast, and fire protection levels.

These solar power glass windows do share some of the benefits of solar panels. The electricity they generate allows building owners to sell electricity back to the main electrical grid and generate income.

“The nanoparticles in the laminate magnify and redirect the light to the edges of the glass, and then into our proprietary window edge frames,” says SAF-GLAS co-founder Art Marino.

However, EnergyGlass won’t produce as much electricity as traditional photovoltaic (PV) panels.
“The glass only features thin strips of monocrystalline cells, located around the edge of the laminated glass panel,” says SAF-GLAS owner Patrick Smith.

“They took a product from the solar industry and married it with a relatively standard glazing industry product” says Steve Coonen, BIPV consultant and principal, PV Glassworks, Grass Valley, California.

EnergyGlass can be used for both new and retrofit applications. It qualifies for numerous local, state, and Federal government rebates, incentives and subsidies that can cover up to 70 percent of total facade project costs.

Currently the company is offering quotes on EnergyGlass installations and anticipates it will be available for sale on the market this first quarter 2012.

Check out more articles by Debra Atlas

For related article, see:
Triple Benefits of Solar-Powered EV Chargers

© 2012 SCGH, LLC.

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Examples of geodesic architecture, which typically use only 40 percent of the lumber of conventional buildings. (Courtesy of TripBase, Inc.)

Editor’s Note: This is an excerpt of “Greenest Places on Earth,” courtesy of Tripbase, Inc.

The earth, like a teenager, is mostly covered in oil, grease and noxious pustules. Occasionally though, you can see a small sign of hope for the future in a clean, vigorous area, glowing with health. In the teenager it’s generally where the acne medication has taken hold, but on the Earth it’s those places where eco-friendly attitudes, words, and thoughts have been put into practice.

Most Eco-Friendly Home: Bear Creek Dome

Geodesic domes had a brief surge of popularity in the 1950s, but they still aren’t a usual shape for a home. This is a pity, because they’re really exceptional for eco-friendly purposes. The Bear Creek Dome in North Branch, Minnesota, has all the usual benefits of a geodesic dome, including increased strength while only using 40% of the lumber of a usual home, and natural heating and cooling. Bear Creek Dome ups the ante by incorporating 16 inches of insulation and triple-pane windows to prevent energy loss. Despite outside temperatures of over 90 degrees, inside the dome the owners enjoy a balmy low 70s—without any air conditioning or power use. Their yearly heating costs are less than $900, despite the bitterly old Minnesota winters.

Read about the most eco-friendly country, city, development, and hotel on TripBase.

For related story: Hippies vs. Treehuggers: the Battle for America’s Greenest City

By E.Q. Lam

SAN FRANCISCO — The EcoCenter at Heron’s Head Park is the city’s first green building that is completely off the power grid. It features on-site solar energy generation, rainwater collection, and sewage treatment—taking advantage of the sun, the rain, and the natural surroundings. “We don’t want to connect to the grid,” says Tracy Zhu, EcoCenter green building design program manager.

The self-sustaining EcoCenter uses sustainable landscaping around the green building and on the “living roof,” in addition to the solar array, rainwater storage system, and wastewater treatment system. The community center is run by Literacy for Environmental Justice (LEJ), which for the past 10 years has been restoring and managing the land at Heron’s Head Park.

LEJ (pronounced “ledge”) also has built a connection with the people in the historically polluted southeast part of the city and beyond. In constructing the EcoCenter, LEJ incorporated the voices of hundreds of community members and built relationships with dozens of industry and government partners to make the center a reality, Zhu says. Companies such as Andersen Windows also joined in contributing to the construction of the center.

The EcoCenter, which opened in April 2010, serves as an example of green building design, community support, and cooperation with government and business entities. It is a sustainable symbol in an otherwise lackluster industrial area. Even though San Francisco is known as one of the greenest cities in the country, Zhu points out, “Who is it green for?” Most parks lie in other parts of the city, while Bayview-Hunters Point bears the brunt of environmental neglect, she says.

“If we look on the east side of San Francisco, the demographic tends to be families of color, low-income families, many more public housing projects than the west side of town,” Zhu says. “So we see this inequality and injustice within the city in terms of distribution of open space. We want to make sure this low-income community is benefitting as much as everyone else.”

Neighboring the EcoCenter is Recology, a company which sorts and ships recyclable materials such as paper and plastics to recycling facilities across the country and abroad. Other industrial neighbors of the EcoCenter are Bode Concrete, a factory; Darling International, a meat rendering facility; and PG&E, a utility company. Also nearby are bus depots and a sewage treatment plant, Zhu says.

“There’s a lot of respect for this building,” says Zhu about the EcoCenter. She points to the absence of tagging, scratching, or other graffiti as evidence of the community’s acceptance of the center.

More than 1,500 students, who LEJ sees as the green generation, visited the EcoCenter even before the building existed. Since the completion of the building, traffic of adult visitors in particular has increased, including policy makers and teachers, Zhu says.

“This area seems hard to reach, but for people who live here, it’s very accessible,” says Zhu. “Our main goal is to connect the local people to local resources. But we go above and beyond that.”

The community has responded positively to the youth employment, free education, and teacher training services that LEJ makes available at the EcoCenter. The center hopes to partner with businesses to offer green jobs training, Zhu says.

Replicating EcoCenter Features at Home

The center demonstrates a multitude of eco-friendly features that can work for the home as well. The environment around the EcoCenter influenced the decisions on what features the building would have, Zhu says—from energy and water sources to building blocks such as energy-efficient windows.

See a tour of the EcoCenter, led by Zhu:

Click here to view the embedded video.

As an energy conservation alternative, the center has a passive solar system which feeds into a battery bank. The center puts to use sunlight, which penetrates through the passive solar glazing on the center’s many windows.

“This forces us to live off the seasonal cycle,” Zhu points out. In the winter, the center would conserve more. The primary consideration for planning the center’s energy use, she says, was the windows and doors.

“Because that’s where you lose it and gain it,” explains Blain Beckmann, a certified green building professional with Andersen Windows. Andersen provided the energy-efficient windows at the EcoCenter.

Andersen, which has a track record as a green company, uses third-party certified sources for its materials, such as forest-harvested materials that are Forest Stewardship Council (FSC) certified. “Over 70 percent of what Andersen purchases is from FSC sources,” Beckmann says. “Being environmentally conscious, it’s no new thing for us. We’ve been around since 1903.”

The company installed two types of sustainable windows at the EcoCenter. The indoor windows, which separate the rooms yet allow heat from the south-facing room to travel through, are made with FSC materials, while the outside, south-facing windows are Fibrex with glazing that allows the path of solar heat gain to pass through. Heat regulation is achieved by closing off sections of the interior windows.

Andersen developed Fibrex windows by looking to re-use material left over from other operations within the company. Forty percent of the fiber in the windows is reclaimed from milling operations and the factory. “We take the sawdust on our floors, we suck it up and use it,” Beckmann explains.

Fibrex windows are three times as rigid as hollow vinyl. The cost of Andersen’s environmentally friendly windows, however, is comparable to the traditional hollow vinyl ones, Beckmann says. “It’s a responsible product for about the same price as regular [windows].”

A major advantage to these windows is that they require no painting. The color will endure for the lifetime of the windows. “These windows should last the life of a home—at least,” Beckmann says. And because they do not need painting, it eliminates one source of volatile organic compounds (VOCs) contributing to bad air quality.

Andersen windows are warranted against rotting and peeling. Dual windows can fail over a longer term due to the expansion and contraction from weathering, Beckmann explains. “By being so stable, we eliminate a lot of that movement,” he says.

With so many windows, the EcoCenter is perfectly situated in one of the sunniest parts of San Francisco. “The number one compliment about this building is how much sunlight it gets and how gratifying it is,” Zhu says.

Other features at the EcoCenter include exposed electrical conduits. They required more planning to bury in the walls during construction, Zhu explains. More importantly, the conduits serve as a teaching tool about the electrical grid, as visitors can follow the energy back to its source. “This is our way of making visible the electrical grid,” Zhu says.

Permeable pavements on the park grounds help capture and filter water. Low-impact landscaping features native plants, which are irrigated with a subsurface system to efficiently feed plants at the roots. The countertops are recycled from bottles, the building façade is reclaimed wood, and the cabinets and sliding doors were re-utilized. Recycled materials make up the artwork displayed in and around the facility.

A Challenge but a Success

Regulatory barriers challenged LEJ in bringing all the features it wanted for the EcoCenter, from building on a landfill to obtaining a certificate of occupancy. The on-site wastewater treatment permit was the most controversial issue, Zhu says. The center is the first building in the city with its own system of this type.

The community center has no connection to the city’s storm water drainage system, either. “Right now we’re not using the rainwater to plumb our toilets, because, again, another permitting issue. But in the future it will be,” Zhu says. “It took many years to get to this point, and hopefully, we’re paving the way for others.”

The services of the EcoCenter are available to the greater San Francisco community. This includes giving Bay Area teachers the opportunity to incorporate sustainability into their curriculum through hands-on learning. As a community center, the EcoCenter also makes itself available for event rental, including as meeting space for companies, government agencies, and the community, as well as space for retreats and family celebrations. Companies such as Salesforce.com have sent workers to the EcoCenter on corporate volunteer days, Zhu says.

The center’s accomplishments were recognized in 2010 with an Environmental Justice Achievement Award from the U.S. Environmental Protection Agency. The next step is to connect the community with the green building industry, Zhu says, by harnessing investment in education programs.

Check out more articles by E.Q. Lam.

© 2011 SCGH, LLC.

Windows let in light, air, and a view of the world. But inefficient windows–as well as inefficient skylights and entry doors–are like holes in your walls and roof. They let out too much heat in the winter and let in too much heat in the summer. And that boosts your energy bill.

The good news is that window technology has made huge strides in the past couple of decades. Today’s energy-efficient windows can be twice as efficient as those sold only ten years ago. They usually have two panes of glass separated by an air gap that helps keep heat from moving between indoors and outdoors. They also block sound, so you won’t be as bothered by Bowser barking next door. Additional features include energy-efficient window frames and heat-blocking coatings for glass.

If you add it all up, today’s energy-efficient windows can reduce energy costs by as much as 15%, depending on where you live. For the average household, that means savings of between $130 and $460 a year for replacing single-paned windows or between $30 and $110 a year for replacing old double-paned ones.

Top Tips

At home

• Caulk first. Be sure to plug leaks and reduce drafts. Even the best window can’t do you much good if you have holes in your house.
• Consider storm windows or shades. Storm windows can be a good, less-expensive alternative to new windows. Also, insulating curtains or shades can reduce drafts.
• Add skylights? A skylight can brighten a dark room and reduce the need for electric lights. Tubular skylights are great for small rooms, bathrooms, and hallways. They’re easier to install, less expensive, and more energy efficient than regular skylights.
• Keep the doors. Fiberglass and insulated steel entry doors are much more energy efficient than solid wood doors. But replacing your door is expensive, and it won’t cut your energy bill by much. It’s more cost effective to block drafts with weather stripping and door sweeps. Adding a storm door is another low-cost way to boost an entry door’s efficiency.

When shopping, look for

• Energy-efficient window frames. Those made of wood are energy efficient but can be expensive, and the exteriors need frequent repainting. Many now come with a protective covering of metal on the outside to make them more weather resistant. Vinyl frames are as energy efficient as wood and much less expensive, but they can expand and contract in hot or cold weather, compromising the window’s performance. Some manufacturers blend vinyl with other materials to make them more stable. The biggest downside is that vinyl manufacturing and incineration creates dioxin, a highly carcinogenic chemical and so its use should really be avoided. Fiberglass frames are also energy efficient and don’t expand or contract, but are more expensive than vinyl. Aluminum frames are inexpensive but the least energy efficient. It’s best not to use them except in the mildest of climates.
• Coated glass. Low-emissivity or “low-e” coatings are a microscopically thin, transparent coating on the glass of energy-efficient windows. Standard low-e coatings help keep the room’s heat inside, making the room feel more comfortable when it’s cold outside. In cold climates, low-e windows can cut heating costs by more than 30% compared with single-pane windows. Other kinds of low-e coatings keep heat in and also block much of the sun’s heat from entering through the windows. This feature can reduce cooling costs by nearly 40% in a hot climate, but is less desirable in cold locations.
• Gases in the gap? In some window products, the gap between the panes of glass is filled with a colorless gas, such as argon or krypton, that’s an even better insulator than air. It’s not clear whether these gas-filled windows are worth the extra money, since there’s no way to tell if the gas leaks out over time.
• Energy Star label. Windows, skylights, and exterior doors with an Energy Star label are certified to meet energy-efficiency guidelines set by the U.S. Department of Energy. You can browse the Energy Star website to see how well products will work in your particular climate zone. It’s also worth checking out the NFRC (National Fenestration Rating Council) labels, which offer even more detailed comparisons.

Other Considerations

• New windows are expensive, so replacing single-pane windows with energy-efficient windows won’t necessarily be cost effective based on energy savings alone unless you plan to live in your home for years to come. However, there are other reasons to replace your windows including making your home quieter and more comfortable. If you’ve done all the easier, less-expensive tune-ups and still have high energy bills, replacing the windows might be the next step.
• If you decide to replace your windows, the least expensive option is installing a new window designed to fit the old window frame. This is commonly done when replacing double-hung windows. But if the frame is in poor condition, you’ll need a new window and frame.
• If you’re remodeling or building a new home, be thoughtful about the size, number and placement of windows and skylights. In hot climates, too much glass on the west and east sides and overhead can drive your air conditioning bills through the roof. In cold climates, glass on the building’s colder north side will make your heater work harder. A good architect can help you design your home properly.
• What to do with your old windows, exterior doors and skylights? Call your local building materials reuse store (aka salvage yard or junkyard) to see if they’ll take them off your hands. If your windows or doors are vintage or have unique architectural features, they’ll be more likely to want them–or you may be able to sell them. Or get creative: old doors can be used as desktops, and old windows can be used as cabinet doors (don’t use them on lower cabinets where there’s a danger that someone could break the glass with their foot or knee).

Benefits…

…to you
No more avoiding sitting next to the window or under a skylight because it’s too cold in the winter or too hot in the summer. Energy-efficient windows, skylights, and doors make your home more comfortable. Energy-efficient windows are also less likely to be fogged with condensation on winter mornings. Special coatings on windows and skylights block UV rays, protecting fabrics, wood, and artwork from fading.

…to the Earth
Energy-efficient windows, skylights, and entry doors reduce fossil-fuel use and greenhouse-gas emissions.

Common Mistakes

• Overheating. In hot climates, large clear skylights may introduce too much heat. Choose skylights with special coatings designed to reduce heat gain, or install small tubular skylights that bring in daylight without as much heat.
• Messing with lead paint. Installing new windows and doors often involves scraping and sanding old paint around the window opening. Take precautions when dealing with any lead-based paint.
• Blocking the winter sun. It’s usually not a good idea to plant evergreen trees on the south side of your house. You’ll get year-round shading and won’t be able to take advantage of the sun’s warmth in the winter. Deciduous trees and vines, on the other hand, will shade you in the summer and bring more heat and light into your home in the fall, when they shed their leaves. (Plants are also champs at absorbing CO2.)

Getting Started

• Check with your local utility company–some offer rebates to homeowners who install energy-efficient windows and exterior doors.
• Choosing windows and skylights can be intimidating. Not only do you have to think about style, materials, and cost, there’s also a wide range of performance issues to consider. A new window or skylight will affect a home’s comfort and energy costs for many decades so it’s important to choose well. Unfortunately, not all architects, builders, or window salespeople have a good grasp of energy-efficient window technology and the pros and cons of various options. If you can’t take the time to become a window expert, at least spend some time tracking down a knowledgeable window professional. Ask local green building organizations or green builders for recommendations.
• If the window frame is in good condition, you can buy replacement windows designed to fit within the existing frame. You can install them yourself if you’re handy, or you can have them professionally installed by a builder or window dealer. If the window frame is damaged or rotting, or if you want to change the shape or size of the window, you’ll need to buy a full-frame window that includes new sashes (the part of the window that includes the glass and the framing pieces directly attached to the glass), the frame (the fixed perimeter that the sashes are set into), and the casing (the molding around the window’s interior and exterior that covers the space between the wall and window frame). Full-frame replacement should be done by a window professional unless you are experienced with building construction.
• Tubular skylights are much easier to install than larger conventional skylights. A professional skylight installer, builder, or handy DIYer can put in a tubular skylight in a few hours.
• For general advice on what questions to ask contractors and other tradespeople, see our “What to Ask Your Contractor” article.
• If you decide you want to study the detailed information on windows, skylights, and entry doors provided by the NFRC(National Fenestration Rating Council), you may encounter some unfamiliar terms. Here’s a decoder:
  • Air leakage tells you how much air will pass through the entire window assembly. A lower number means less air leakage. Manufacturers of lower-quality windows may not include an air leakage number.
  • Condensation resistance is a measure of how well the window will resist the formation of condensation on the inside of the glass. A higher number is better.
  • Solar heat gain coefficient (SHGC) indicates how much of the sun’s heat will enter through a window. The higher the number, the more heat will enter your home. An SHGC of 0.40, for example, means that 40% of the sun’s heat gets through the window.
  • U-factor tells you the window’s resistance to heat flow. The lower the U-factor, the better the window is at keeping warmth inside your home. (Those low-e coatings mentioned above help lower a window’s U-factor.)
  • Visible transmittance tells you how much light (as opposed to heat) the window lets in. Lower numbers mean more daylight is blocked.

The right window treatment can help turn a room from drab to divine. It can also save energy, keep you more comfortable, and even make your home healthier. If that sounds like a lot to ask of a mere shade or shutter, read on to find out just how green today’s window coverings can be.

Top Tips

• Go for quality. Buy the best quality window-covering products you can afford, especially when it comes to hardware like the traversing mechanisms on draperies and the spring mechanisms on roller shades. Window coverings that hold up over time are less likely to wind up in the trash.

• Keep heat out. On hot summer days, close window coverings on the east, west, and south-facing windows to keep out the sun’s rays (the north side doesn’t get direct sun). Window treatments with a light-colored backing help reflect the sun’s heat back outside. Some companies sell special solar-control shades designed to block the sun’s rays while letting in some daylight. Other good options include blinds and louvered shutters; you can tilt the slats up or down to direct sunlight back outside.
• Keep heat in. When the weather turns cold, insulated window coverings can help keep warmth inside and cut down on drafts. A curtain or shade lined with thick insulating fabric will do the trick, as long as it fits snugly within or around the window jambs so air doesn’t circulate around it. Honeycomb shades (also known as cellular shades) can also keep your home warmer: these have double or triple layers of accordion-pleated material that traps air between the layers.
• Mind your materials. Every material has environmental impacts, but some are easier on the planet than others. If you want to steer clear of petrochemical-based synthetics like polyester, acrylic, or vinyl, you’ll still have loads of options, including curtains made from cotton, wool, silk, linen, and hemp. Choose certified organic textiles when possible; if you can’t find premade organic curtains, you can buy organic fabric and sew the curtains yourself or have someone sew them for you. Other natural-fiber options include shades made from paper, reeds, bamboo and other grasses, and wooden blinds and shutters (choose FSC-certified when possible). Recycled polyester drapery fabric is another green, albeit synthetic, option. Steer clear of polyvinyl chloride (PVC or vinyl) window treatments; vinyl has been linked to a number of health and environmental problems.
• Play it again, Sam. Giving used window treatments a second life is a great way to be green and save a little green, too. Look for used shutters, blinds, curtains, and curtain rods at salvage yards, flea markets, thrift stores, and Internet classifieds sites. But don’t buy older vinyl blinds (see “Other Considerations,” below), and be cautious about old painted shutters that may have lead-based paint.

Other Considerations

• Exterior shading devices. Interior window coverings can help keep your home cooler in the summer, as noted above. But it’s even more effective to block the sun before it hits the window by shading the outside of the window. Above south-facing windows, an awning or overhang doesn’t need to be very deep to provide good solar control in the summer when the sun is higher in the sky. In the winter, the shallow awning or overhang will allow in the low-angle winter sun, helping warm the home. If you have a passive solar home, it’s particularly important that the overhangs not be so deep that they block daylight or winter sun. West- and east-facing windows are harder to shade with exterior awnings and overhangs because the sun comes in at a low angle; exterior operable shutters may be a better bet for keeping out heat and blocking glare. Shade trees and vines on trellises are another good green option for natural cooling.
• Lead in vinyl blinds. In 1996, it came to light that overseas manufacturers of non-glossy vinyl blinds (also called Venetian blinds or mini-blinds) were adding lead to the plastic as a stabilizer. Over time, as the mini-blinds were exposed to heat and light, the vinyl would deteriorate and lead dust would form on the surface. Young children were at particular risk of lead poisoning because they would touch the blinds and then put their hands in their mouths. Vinyl blinds made after 1996 are lead-free. If you have vinyl blinds that might predate 1996, consider throwing them away, especially if there are young children in the home. If your town has a household hazardous waste collection facility, put the blinds in a plastic bag and take them there; if not, put them in a plastic bag and discard them in the trash. Don’t put discarded vinyl blinds on the sidewalk where someone else might take them, and don’t buy used vinyl blinds.

Benefits…

…to your health
If you’re looking for fabric window coverings, your best bet may be to shop at a retailer that specializes in green home products. That’s because home-furnishings textiles may be treated with a variety of chemicals to reduce wrinkling, resist stains, or retard flames. Because there are no labeling requirements, it’s very hard to know what chemicals have been used on fabric window coverings. You can try asking the retailer or calling the manufacturer, but be aware that you may not be given an informed answer. Even when shopping at a green retailer, be sure to ask questions if you’re concerned about getting window coverings without added chemicals.

In urban and suburban areas, light pollution from streetlights, lighted signs, passing vehicles, or the neighbor’s porch floodlight can keep people awake at night and may even alter circadian rhythms. Disruptions of human’s circadian clock have been linked to insomnia, depression, cancer, and other health problems. To get a better night’s sleep, consider outfitting bedroom windows with roller blinds, shades, or curtains that have a light-blocking blackout liner.

Window coverings are notorious dust collectors. For better health, choose products that are easy to keep dust-free, especially if there household members have dust allergies or asthma. Plantation-style shutters with wide louvered slats, for example, are easier to dust than floor-to-ceiling velvet curtains. For curtains, choose materials that can be laundered at home instead of having to be dry cleaned.

…to your wallet
Energy-efficient window coverings can lower your heating and cooling costs. Window coverings can also protect furniture, floors, and carpets from damaging ultraviolet rays.

…to the Earth
Energy-efficient window coverings reduce your emissions of climate-changing greenhouse gases. If you choose durable products, you’ll also reduce the resources needed to cover your windows over the lifetime of your home.

Common Mistakes

• Piling on the layers. Swags, valances, cornices, and multiple layers of draperies and shades may give your room a certain je ne sais quoi, but all those products take their toll on the environment, not to mention your wallet. When it comes to the environmental impacts of consumer products, less is often more.
• Letting pull cords dangle. Make sure that looped pull cords on shades, blinds or drapes aren’t within reach of young children or pets—they can get entangled in them and strangle. Avoid products that have looped pull cords, or keep the pull cord well out of reach.

Getting Started

You can buy the greenest window treatments in the world, but in the long run it’s your behavior that matters most. Close window coverings on hot summer days and cold winter nights to save energy.

Related Products and Services

• Free and Low-Cost Solar Energy
• Furniture
• Windows and Skylights