Windows 101: Tips for selecting the right window for your home
If you’re thinking about building a new home, or remodeling your existing one, you may wonder about how to select the best windows for your project.
Before you begin, consider this: windows affect the appearance of both the inside and outside of your home and can make a huge different in your overall level of comfort and enjoyment in your home. Take time to learn more about the virtually limitless style and function options to maximize your window investment and enjoyment for many years.
Elements to consider
- Appearance — Choose a window that will look good from the inside as well as the outside of your home. For maximizing light flow into the home, rather than keeping an insect screen in place all year, consider a window with a screen that rolls up and out of sight when not in use, or one that is engineered to allow more natural light and air to flow through.
- Energy efficiency — Get the facts about factors that relate to energy efficiency, like U-values and Low-E insulating glass with argon* windows and weatherstripping. U-values measure the insulating value of windows and other fenestration products. The lower the U-value, the better job a window does in keeping out heat and cold (which is the opposite of R-value — the higher the R-value, the better insulation in the walls and ceilings). A low U-value is important in all climates. In Southern climates where air conditioning is important, choose a window with a lower solar heat gain coefficient (SHGC) to block more of the sun’s heat rays. Compare efficiency ratings before you purchase a window to help lower heating and cooling costs and make the most of your investment.
An easy way to choose energy-efficient windows is to look for products that meet ENERGY STAR® requirements. The ENERGY STAR program was created by the U.S. Environmental Protection Agency and the U.S. Department of Energy to help consumers identify windows and other products that save energy. Performance requirements for windows are tailored to meet the specific needs of different climates. For example, in Southern climates in the U.S., a low SHGC is most important. In Northern climates, a low U-value is most important. ENERGY STAR qualified windows assure homeowners the windows they choose are the most appropriate for their area in terms of energy efficiency.
Most high-performing windows today have glass coated with a Low-E microscopic film. The Low-E coating improves thermal performance and stops much of the sun’s heat rays and damaging UV rays while only slightly tinting the window. Read more about Low-E coating in the Glass types and options section of these tips.
- For more information about energy efficiency and window terms, read "Confused about R-values and other window and door terms?" on the Pella Pressroom or go to the Consumer Information section of the National Fenestration Rating Council website at www.nfrc.org.
- Function — Test the ease of operating a given window style before you buy it. Does it open smoothly? Is it easy to clean? If it’s a casement window, does the crank handle fold away to leave window fashions undisturbed? Keep in mind where the window will be placed — will it be easy to open, for instance, if it’s over the sink or another hard-to-reach spot? If the window will be a means of an escape exit in case of fire, make sure it opens easily and provides an adequately-sized opening to meet the needs of local building codes for emergency exits.
- Installation — Window installation may be relatively straight forward or may be quite complex. If you are considering enlisting the services of a professional, it may be wise to inquire about installation services prior to purchasing your windows.
- Location — Keep in mind which direction your windows will face and how much sunlight or weather they will be exposed to. Sometimes you can get too much of a good thing — oversized windows featuring standard glass can allow too much hot sun into a home during summer months. Consider selecting windows with between-the-glass shades or blinds for enhanced privacy. Select windows featuring Low-E coatings to protect your furnishings from overexposure to the summer’s hot sun.
- Maintenance — How important is exterior maintenance to you? For the ultimate in convenience, consider virtually maintenance-free aluminum cladding that will keep your windows looking beautiful for years to come. Are the windows designed for ease of cleaning from the home’s interior? Are grilles protected between panes of glass to make cleaning a breeze? Are hardware options easy to maintain and operate?
- Options — Don’t forget about the importance of color options in reflecting your style and adding to the appeal of your home. Some manufacturers offer limited exterior colors choices, while others offer custom colors to match your decor. The sky’s the limit when it comes to color choices, from standard options to custom colors to reflect your unique style. And color doesn’t end with the window itself. Today’s window hardware coordinates with other hardware options in your home, such as cabinetry hardware, faucets and other fixtures.
- Personal preference — What style of windows do you prefer? Classic or contemporary? With grilles or without? If you make a quality window purchase, you will likely live with your decision for many years. Select a style that reflects your preference.
- Price — Shop around, and remember, you get what you pay for. The least expensive window probably isn’t your best buy. A good quality window should provide decades of beauty and performance.
- Purpose — Choose the right style and size for each window. Do you want the window to frame the view outside or simply provide ventilation? Will it function as an operable window or will it be a non-opening decorative accent for the outside of the home?
Choosing a window style depends on your home’s architecture, the purpose or function of the window, and finally, your budget.
- Awning — This casement-type window, hinged from the top, opening outward from the bottom, generally has less air leakage, because the sash closes by pressing against the frame. Because of this design, awning windows shed water away from the window opening. Awning windows are typically installed over fixed windows or doors (as transoms), or in garages above eye level to provide ventilation and privacy at the same time. They are a good choice for windows that are wider than they are tall.
- Bay and bow — A typical bay window consists of a large center window bordered on either side by double-hung or casement windows set at 30- or 45-degree angles. All the windows can be stationary (fixed), operating (venting), or any combination of those. The bow window, similar to a bay window, consists of four or more equal-size windows, usually casements, that create a gradual arcing projection. Both bay and bow windows provide great open views, as well as give a room the aura of being larger than it really is. Adding a window seat is a popular addition to any bay or bow window.
- Casement — A popular style featured in a wide variety of home designs, casement windows feature a single sash that’s hinged on the left or right and opens using a crank handle. That’s why they’re sometimes referred to as “crank out” windows. Casement windows offer more ventilation than double-hung windows, typically have less air leakage than other window styles, and look best if they are at least slightly taller than they are wide. Because they swing out, however, they may not be well suited to installation adjacent to heavy pedestrian traffic areas, such as decks or front porches.
- Double-hung — Double-hung windows feature two sash in a single frame. The top and bottom sash bypass each other vertically when sliding open from the bottom up or the top down. Double-hung windows look best when they are about twice as tall as they are wide and the each sash is an equal-sized square. They are often installed in traditional or Victorian homes, or those featuring a classic or Colonial style.
- Fixed — Often selected for decoration or in combination with other windows, fixed windows don’t open or vent. A circular or hexagonal window can be strategically placed to enhance a view or the exterior architecture of your home. Or, in a window wall, a fixed window can be flanked by venting units and topped with smaller fixed units, called transoms.
- Single-hung — Single-hung windows offer all the features and benefits of double hung windows, with one difference: only the bottom sash opens by sliding upward. The ventilation opening can be adjusted from a small area to one-half of the window area.
- Sliding — Sliding windows, sometimes called gliders or sliders, function just as their name implies — moving horizontally side to side. Sliders are one of the most sleek, contemporary profiles in windows, and ideal for installing in those hard-to-reach areas, like over the kitchen sink. They also are commonly installed in multi-family buildings and apartment complexes. Sliders are typically available as single-sliding (only one sash moves) or double-sliding units.
- Transom — Like fixed windows, transoms are most often used in combination with other windows, and can be either venting or fixed units. They typically are installed underneath the primary window units, or on top of a room’s primary windows. They help give a room the illusion of larger windows, allow in more light and, if venting units, may increase airflow. Transoms often are used to create a window wall. Transom windows are available in many different shapes, including square, rectangular, half-circle, elliptical, and many more.
- Window wall — Also often referred to as combination windows, window walls help make a small room look larger maximizing the amount of light and ventilation. They are literally a wall of windows in any combination of sizes, shapes and styles, sometimes stretching from floor to ceiling and wall to wall.
- Clear — Clear glass is the basic material available for windowpanes. In recent years, with the advent of ever-increasing energy costs, more homeowners are choosing glass with special glazing options, like Low-E coating, to enhance energy efficiency.
- Low-E — Low-E coating is a microscopically thin finish of metal oxide on the surface of clear glass that reflects a high percentage of heat. This coating allows the sun's heat and light to pass through the glass into the home, while at the same time blocking heat from escaping the room, considerably reducing heat loss.
- Heat absorbing — Glass treated with gray, green or bronze tints reduce heat gain by absorbing as much as 45 percent of the incoming solar energy, further increasing the energy efficiency of windows.
- Reflective — Glass that has been coated with a reflective film is useful for controlling solar heat gain during the summer. It also reduces the passage of light and solar transmittance year-round.
- Glass layers and air spaces — Homeowners can choose from one, two and sometimes even three panes of glass for their new windows. 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 increasing 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.*
When purchasing new windows, one important consideration is the type of material used to make the window sash and frame. Now more than ever before homeowners have a choice of several materials.
- Aluminum — While less expensive, aluminum windows are less energy efficient than windows made of other materials. Aluminum windows may experience conductive heat loss and condensation around the frame. If your home is equipped with aluminum windows, you may feel more heat or cold when you are near your windows. Another drawback is that while they can be painted to accommodate a color change to a home’s exterior, the paint job may not be as natural looking as paint on wood or fiberglass.
- Fiberglass — A relative newcomer to the window industry, fiberglass windows are some of the most energy efficient windows, because they do not warp, shrink, swell, rot or corrode in varied climates. Because of their thermal stability, they are excellent for holding large expanses of glass. Fiberglass windows are typically more expensive than aluminum or vinyl.
- Vinyl — One of the most popular materials, vinyl windows are durable, generally lower cost, and energy efficient. While they are typically available in a wide variety of light colors, one drawback is they cannot reliably be painted another color if the home’s exterior changes, because paint doesn’t adhere well to the vinyl. Another consideration is climate. In areas of extreme heat, vinyl windows may get soft or sag, compromising the seal between the glass and the frame. Repeated exposure to extremes of heat and cold may cause the windows to become less energy efficient.
- Wood — The first material in windows and doors, wood windows are still a wise choice for many homeowners trying to upgrade a home’s original windows with more energy efficient models. Wood windows produce higher R-values, are unaffected by temperature extremes, and are less prone to condensation. Many wood windows feature aluminum or vinyl cladding on the exterior, which reduces external maintenance.
- Different climates require different window technologies and materials for optimal performance. Be sure to check with the experts at your local window store to determine the best options for you.
- Read about "When to replace windows" and "Look for the ENERGY STAR® logo" on the Pella Pressroom for more information.
*High-altitude Low-E insulating glass does not contain argon.