If “eyes are the windows to your soul,” as Shakespeare so eloquently suggested, we would argue that windows may just be the eyes of your home. Not only do they bring in air and sun that comfort body and spirit, but their transparency to the world outside also brings in light and views that nourish the soul.
Long gone, however, are the days when window selection, whether for a new or existing home, was a fairly simple matter. Today, aesthetics and beauty matter. Materials matter. Performance matters. And they especially matter in a state like Minnesota, with our dramatic high and low temperatures, aridity, humidity, rain, snow, and wind through the seasons. But where is a homeowner to start?
Well, at square one. Are you building new, remodeling, or replacing? Your answer will set you on the path to selecting the right windows for your home.
“When a homeowner comes into our showroom, the first thing we ask is whether they’re remodeling or building new,” says Kolbe Gallery Twin Cities general manager Lance Premeau, CSI, CDT, LEED Green Associate. “If someone is doing a remodel, they’re mentally tied into the style and materials they have currently in the house. They most likely think they need new windows to match what they have.”
Conversely, Premeau continues, homeowners selecting windows for a home they’re currently in the process of building “are free to use their imagination on what the home will look like aesthetically and architecturally. In either case, we ask specific questions to understand the homeowners’ goals, whether they’re related to energy and performance, aesthetics, functionality, or longevity. We start at zero to really focus in with the homeowner on their desires and on what we can provide.”
But with homeowners seeking to replace the current windows in their existing home, “they’re usually looking to address a certain issue,” adds Clive Rugara, senior business director for Andersen Windows & Doors’ top-of-the-line 100 Series, 200 Series, and 400 Series. “That issue might be structural, like eliminating water damage. Or, they may want to change the style of their windows or improve energy efficiency.”
With gas and electrical costs currently skyrocketing, considering this energy efficiency component Rugara speaks to is a promising place to begin—whatever your situation may be. “Each year, the average American household spends $1,500 to $2,500 on energy bills,” states the National Fenestration Rating Council (NFRC) on its website. “Forty-five percent of that cost is for heating and cooling.” For homeowners remodeling or replacing windows, a home energy assessment or audit (which can help you determine how much energy your home uses, where your home is inefficient, and which problem areas and fixes you should prioritize to save energy and improve the comfort of your home) is a great next step.
And, you guessed it: Windows are a common problem area, as they’re an integral component of the home’s building structure and envelope. By ensuring they’re as energy efficient as possible, homeowners can reduce heating, cooling, and lighting costs. New windows can also improve comfort in the home by reducing noise, eliminating drafts, lessening heat gain during the summer months, and allowing heat and warmth into the house during the winter.
Let’s Get Technical
When window shopping, you’re going to come across myriad terms and acronyms that may feel a little foreign. What do they mean? What values are considered “good”? Here, we dig into the biggest “need to knows” while perusing your potential picks.
Let’s start high level. You may be familiar with the term ENERGY STAR, which is a program and rigorous set of requirements created by the U.S. Environmental Protection Agency and U.S. Department of Energy to assist homeowners in identifying home products (especially windows) that save energy. If a product meets ENERGY STAR requirements, you can be certain it is an excellent choice for energy efficiency.
In the North, a low U-value is also an important consideration. A U-value, also known as thermal transmittance, is the rate of heat transfer through the window—in other words, how well a window keeps heat inside your home. The lower the U-value, the better the window is at keeping out (or in) heat and cold. A factor of 0.30 or lower is what you should aim for in cold climates.
Another acronym you’ll see while window shopping is SHGC, or solar heat-gain coefficient. According to the International Association of Certified Home Inspectors, “the amount of solar radiation that can pass through a window or skylight can be measured in terms of its SHGC,” which is another rating used to help quantify the energy efficiency of windows and skylights. For example, a SHGC rating of 0.40 means 40 percent of available solar heat is able to pass through the glass. The NFRC informs ENERGY STAR ratings, which suggest an SHGC of 0.35 or more for homes in the Northern climate zone.
Visible transmittance, or VT, refers to the visible spectrum of sunlight (measured in nanometers) transmitted through the glass. VT is expressed as a number between 0 and 1, and should be determined by your home’s daylight requirements and/or the need to reduce glare inside your home. If you want lots of sunlight, choose a window with a higher VT value. Most windows measure between 0.30 and 0.70.
Also, be aware of the light-to-solar gain, which is the ratio between the VT and SHGC. This ratio gauges the efficiency of various glass and glazing types in transmitting light while blocking heat gains. The higher the number, the more light is transmitted without adding excessive amounts of heat. (This is critical during those scalding hot summer months.)
If you see “Low-E,” which stands for low-emissive, on a window, that means the manufacturer has applied a microscopically thin, transparent finish of metal oxide on the surface of the glass. Its purpose? Reflect heat. Pella, another window manufacturer, details its function further online, explaining how the coating “allows the sun’s heat and light to pass through the glass into the home, while at the same time, blocks heat from escaping the room, considerably reducing heat loss.”
Homeowners might also encounter heat-absorbing glass, which has been treated with colored tints to reduce heat gain. These tints absorb massive amounts of incoming solar energy, further increasing the energy efficiency of windows. There’s also glass coated with a reflective film, which can help reduce heat gain in summer.
Enough of the nitty gritty. What’s all this talk about single-, double-, and triple-pane windows? According to Pella, “A single-pane glass is the least energy efficient option, providing only a thin barrier to the outside elements with very little insulating value, as evidenced by its high U-value. Multiple layers of glass increase a window’s ability to resist heat flow (decreasing the U-value) and greatly increase its energy efficiency. An even more energy efficient window results when the double- or triple-paned glass is a Low-E insulating glass with argon.” Argon, which is an odorless, colorless gas that window manufacturers use to improve thermal insulation, can slow air movement and improve thermal performance.
That’s not all. Homeowners selecting new windows need to balance these concerns with the direction each window faces (for instance, in the North, we like our south-facing windows to bring in lots of sun and warmth in the winter but not so much in the summer); how much sunlight you want to bring into each room; and your energy or building performance goals. “You have four sides to your house,” says Premeau of Kolbe Gallery. “On one side, you might want a different glass type than on the other sides to take advantage of or block the sun.” Thankfully, you don’t have to figure this out all on your own. Experienced local pros and even a window selection tool like the one provided by efficientwindows.org help homeowners make the best choices.
But let it be known: No window, regardless of how many panes or coatings it has, is worth the cost if it’s not constructed and installed correctly—which can eliminate the energy efficiency you had hoped for. “Look for how a window performs and make sure that it’s constructed with energy-saving and sturdy materials, but also investigate how it will be installed,” advises Rugara of Andersen. “Installation is critical. When you combine the right glass with superior framing and installation, you get the performance you’re looking for.”
Just as homeowners “can change glass coatings to fine tune energy performance,” Premeau says, “they can also fine tune the materials they choose for the window sashes and frames.”
First, some basics: Aluminum sashes and frames are the least expensive, but this metal is also less energy efficient than fiberglass, wood, vinyl, or steel. Aluminum windows may result in conductive heat loss as well as condensation around the frame.
Fiberglass, on the other hand, is more energy efficient, plus high-quality fiberglass sashes and frames won’t warp or corrode. These window frames also resist dents, bends, and breaks, limiting expansion and contraction to help improve energy efficiency. They also reduce the risk for seal failure and provide long-term, dependable performance.
Vinyl is a popular material for window frames as it’s durable and energy efficient. (One drawback is that vinyl can be difficult to repaint should a homeowner decide to change the color of the home’s exterior or interior.) Also, extreme heat and cold cycles, as we have in the Midwest, may cause vinyl windows to wear and become less efficient over time.
Wood, of course, is a well-loved choice for its durability, beauty, and aesthetic adaptability. Wood-framed windows, depending on the type of wood and style of the framing, look nice with nearly every style of house. Wood windows also produce higher R-values than many other materials. (The R-value refers to a material’s resistance to heat flow and is measured in terms of its thermal resistance. A higher R-value reflects greater effectiveness of insulation.) Wood windows are also often clad in aluminum or vinyl to reduce maintenance.
Steel-framed windows, while the most expensive option, are also the strongest, most durable, and most secure selection. Whether of galvanized steel, stainless steel, Corten steel, or brass for a bronze-like appearance, steel windows are most often selected for homes with a contemporary, modern, or industrial aesthetic. Steel can also be combined with other metals or wood, providing homeowners with yet more options in framing.
Just as homeowners may select certain glazing or coatings for windows on the north, south, west, and east sides of their house to maximize performance, location and planned uses will also determine framing materials—and not just on the exterior. “An entire home may have wood interior frames,” Premeau explains, “but you don’t want a wood window frame in bathrooms or shower rooms. A fiberglass frame or composite material that’s impervious to water would be a better choice.”
One of Kolbe’s best window lines, Premeau adds, is the Forgent Series, made of a proprietary fiberglass composite called Glastra. “The line has been available for five years,” he says, “but we just added a new type of weld for the sash and frame that provides a stronger bind and more complete seal for better energy performance. It’s also more aesthetically pleasing as the joint is clean and streamlined.”
How We Live Now
Just as manufacturers continue to modify existing window lines to improve aesthetics and performance, so are homeowners becoming more educated about their options. Clients who are building a new home, for instance, says Rugara, “are really examining how they want to live and interact in the home, and how windows play into that.”
Along with researching window manufacturers and studying the information on their websites, homeowners are avidly consulting HGTV, Pinterest, Instagram, Houzz, and magazines like ours to collect pictures as they plan their new home. “They’ve researched windows before they come into our showrooms and often start from a dream stage,” Rugara says. “We then help them work their way back in terms of how to achieve those goals.”
One trend that’s huge right now is large expanses of glass, whether through windows or doors. “People want an unobstructed view to the outdoors,” Rugara says. “In contemporary or more minimal house design, it’s about glass and how that glass becomes a transparent wall. It provides protection from the outside but gives you open, natural light and interaction with the outside world.”
But there are drawbacks. “A large glass opening is very appealing on screen,” says Premeau. “Our job is to ask homeowners how often this door or window they’ve envisioned will be operated, how they’re using that space inside and outside, and whether it makes sense given their budget.”
There’s more. “Large glass doors usually come with an unobstructed sill,” Premeau adds. “That typically means those doors don’t have the best performance at keeping water out. We ask the homeowners whether there’s an overhang, what floor the door is on, and which direction it’s facing. As window specialists, it’s our job to pipe up if we think a homeowner is headed for trouble.”
In the last two years, as people are hit with realities of climate change and an ongoing pandemic, their ideas about windows have also changed. “Many people now live, work, and play at home,” explains Rugara. “Our sense of security at home is different. Home is a bubble. More and more homeowners are trying to figure out how windows play an important role in that mindset.”
The eyes of our homes—bringing in light, views, warmth, and beauty—are growing larger with possibility. “Being able to look out and see the world, to feel as though you’re outside when you’re inside, and the idea of indoor/outdoor living is really booming,” Rugara says. “People are considering this when building new homes or when remodeling to open up their interior spaces. We’re often asked to replace three or four windows with two big ones. At Andersen, we offer a broad portfolio to address these challenges and to provide opportunities for people to realize their dreams.”