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What You Need to Know About Windows
By Janice Booth

An octagonal window that provides light but is frosted for privacy.

"When I look from the kitchen out our windows, what I see of nature is more beautiful than the greatest painting. That is what I want my windows to do, frame nature." Like many homeowners, Severna Park residents Pil Ju Templeton, watercolorist, and her husband, Dr. Richard Templeton, recently replaced windows in their 50-year-old home overlooking the Severn River. The Templetons found the project arduous.

Selecting windows may seem fairly straightforward-if you know the limitations of your budget and the difference between a window jamb and a sill; what grids are; and whether a window is double-hung, casement, or a slider. There is quite a bit more to windows than meets the eye.

In addition to your budget and the integrity of your home's appearance several other considerations are important when you select windows for a new home or as replacements: durability, energy efficiency, and knowledgeable installation.

A simple 2 vertical pane window.

In brief, a window for a home in Anne Arundel County should probably be framed in vinyl or wood and have a vinyl cap. Inside the vinyl frame, double panes should be separated by polystyrene warm-spacers sealing the argon gas insulating layer between the two panes, with a low-E coating on the inside of one pane.

What do those recommendations mean and what are the reasons for them?

A Good Window Is a Feat of Engineering Efficiency

Installing new windows is a major investment of time and money. The durability of those windows, clearly an important feature, depends on the material used for the frame, how the glass is secured in the frame, and how the window is installed in your home. These characteristics do not significantly affect the window's appearance architecturally, but they do affect your budget, both in the immediate construction plan and over time.

Vinyl is commonly recommended as the best choice of window frame material for homes in Maryland. Considered strong, durable (with an average life span longer than 20 years), reasonably priced, and easy to maintain, a vinyl frame retains its color and finish and can be manufactured in almost any traditional or contemporary window style. In addition, a properly designed vinyl window has excellent insulating properties.

Window Facts At the National Fenestration Rating Council's site, www.nfrc.org, you'll find helpful information on how windows are rated and clarifications of the latest innovations and research. Also there are fact sheets, such as "The Facts About Solar Heat Gain & Windows." The Efficient Windows Collaborative is an organization similar to the NFRC. Its Web site, www.efficientwindows.org, provides computerized configuration as well as useful diagrams and easily understood explanations of the factors you may need to consider in choosing your windows. The University of Central Florida has established the Florida Solar Energy Center (FSEC) to encourage the use of energy-efficient and environmentally sound windows capable of withstanding the extreme weather conditions of Florida's climate. The FSEC's Web site, www.fsec.ucf.edu/bldg/active/fen, reports on issues such as what type of window construction can best withstand hurricane-force winds.

Window frames can also be made from aluminum, wood, vinyl-covered wood, and fiberglass. Aluminum is the least expensive frame material to buy but the most expensive over time because of its poor insulating properties and susceptibility to corrosion. The poor durability this produces means aluminum frames last on average 10 years. Aluminum frames can be designed to compensate for the material's weaknesses, but the added cost makes them comparable to vinyl frames.

Traditional wood frames insulate well and are energy efficient and attractive, but they require regular maintenance for durability. Properly maintained, they last more than 25+ years. Wood frames can be bought with the exterior or entire frame sheathed in vinyl, giving the window a traditional look without the high maintenance.

Fiberglass is the newest framing material. Though it does require painting, it is exceptionally strong and durable (lasting up to 40 years), particularly for coastal regions where salt water, wind, and storm damage are possible. So, if you're redoing a beach house, you may want to look into fiberglass frames.

Once you've decided what the window's frame will be made from you must decide on the glazing, or glass, specifically the number of sheets of glass (single, double or triple pane) each window will have. For our moderate climate, double-pane windows are usually recommended. Single pane, or glazing, wastes energy and triple glazing does not provide significant cost-to-benefit advantage.

The wisest selection of window frame material and glazing can be all for naught if the windows are constructed poorly or installed improperly.

A traditional 6 pane wood window.

The glass doors and adjacent glass windows give this Victorian style home distinctive character.

The gothic arch of this domed window allows more light to enter the home.

A Cautionary Tale

In 2001, Annapolitans Julia and Jerry Pruchniewski thought everything would go smoothly for them when they had their townhouse windows replaced. Before proceeding with the project, they communicated with the architectural committee of their homeowners' association. "We chose to contract for our new windows with the company that was working on the townhouses already. We knew the association had looked at the contractor's work and taken bids to ensure cost-effectiveness," Julia recalls.

Despite their precautions, a seal of one of their large living room windows broke. They first sought redress from the company that installed the windows, only to learn that the company had been dissolved and the contractor is living somewhere in West Virginia. The Pruchniewskis then turned to the windows' manufacturer. After all, the windows had a lifetime warranty. The manufacturer initially blamed the problem on the installation, forcing the home owners to prove that the window's damage was indeed a structural flaw. Reluctantly, the window manufacturer honored its warranty and agreed to replace the defective window. The question remains, will the manufacturer pay for removal of the original window and installation of the new window as well?

Even faced with these problems, the Pruchniewskis have no regrets about their decision to replace their inefficient window. "We've realized huge savings in our heating and air conditioning costs. The house is so much more comfortable; it feels warmer in the winter and cooler in the summer," says Julia. "We used to watch the drapes rustle when a winter wind blew through. Now, the drafts are gone."

A Window Into the Future Window design and engineering is a dynamic field. Attention has turned to developing windows more resistant to extreme weather conditions-hurricane winds and tidal water surges. Experiments are also under way that incorporate wiring into windows, opening the way for "smart" windows that self-regulate the transmission of air, heat, and light. Imagine an early spring morning-your windows with southern exposures might open to let in the warm sunlight while the windows with a northern exposure, where a chill breeze has arisen, might remain closed. Finally, state-of-the-art, energy-efficient windows provide more light and better protection from adverse weather conditions while saving you money. Not only will your new windows perform better, but your household will perform better too.

Using Consumer Facts to Your Advantage

With more than 56 million residential windows manufactured and installed in 2004 mistakes are bound to be made. You don't want them to be made at your expense. The National Fenestration Rating Council (NFRC) monitors window manufacturing and installation practices. (Fenestration is the openings-windows, doors, and skylights-or their placement, in a building.) The NFRC is an organization of manufacturers, builders, and distributors of windows, doors, and skylights. The council has worked since 1992 to monitor government energy policies and ensure that its members offer products that meet current construction and energy standards. The U.S. Department of Energy and other organizations with similar concerns defer to the NFRC's self-regulation and ratings.

When contracting for your windows and installation look for a long warranty period from the window manufacturer, which reflects its confidence in the windows' seals and frame construction. Ask for references from the contractors you're interviewing to install the windows. How long have the contractors been in business, and have the window installations they've completed for other homeowners held up over time?

Energy Efficiency Is Money in Your Pocket

In its effort to measure energy efficiency and provide the public with useful data, the NFRC uses acronyms for the relative energy conservation characteristics of a particular window design and it has developed an energy rating label for windows similar to the Energy Star designation for appliances. On the label, you'll see SHGC, U-factor, Low-E coating, VT, AL, and perhaps CR, measurements that indicate key factors in a window's energy efficiency-or lack thereof.

Look for the label and ask sales representatives to discuss their windows' ratings. The large, square label with the NFRC logo should be affixed prominently to model windows.

Janice Booth is a freelance writer and adjunct professor at Anne Arundel Community College, teaching public speaking and journalism.

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Window Acronyms

The entire back half of this house utilizes French doors and windows to integrate the back patio and pool with the interior of the home. Additional angled walls and a double bank of windows create an alcove full of light and drama in this contemporary living room.

Factors rated by the National Fenestration Rating Council and recommended ratings: The U-Factor measures the quantity of heat or cool air allowed to escape through the window. below 0.4*) Solar heat gain coefficient (SHGC) is the ratio between the amount of harmful ultraviolet rays deflected and the amount of sunlight allowed in. (below 0.4*) Visible light transmittance (VT) measures how much sunlight is allowed through the panes. (above 0.6*) Air leakage (AL) measures the escaping air from the interior and the air entering from around the frame. (below 0.37*) Condensation Resistance (CR) may also be included. Manufacturers can choose to show this rating or not. (the higher the better*) * Preferred NFRC rating Light transmittance, or VT, is fundamental to window design and placement. In the summer, windows should deflect heat and allow sunlight into the interior. In winter, both heat and sunlight are desirable. Present engineering requires a compromise, though there are prototypes for "smart" windows that adjust sun and heat transfer depending on exterior temperatures. For now, VT ratings are improved by low-emittance (Low-E) coatings that turn aside the sun's heat yet welcome sunlight. Dark tinting, an early but crude solution, has been replaced by metallic or metallic oxide coatings that can be applied to an inward-facing pane in a multipane window. Another method is the insertion of a plastic film between the panes. These barriers repel heat and harmful ultra-violet rays and allow sunlight to pass through. Spacers made of traditional insulating material, such as polystyrene foam, can prevent drafts or air loss (AL) and the condensation and fogging (CR) that occur over time when seals break and air or moisture settles along the edges of the glass and seeps between panes. In addition, insulating characteristics can be enhanced by replacing the air between panes with argon or krypton gas, inert gases that absorb and deflect heat and sound.

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A Big Window on Pricing

It's difficult, if not impossible, to quote prices; there are too many variables. For example, Gary Dymski, in a Newsday magazine article, estimates that a 2½-foot by 4-foot, double-pane vinyl window will cost from $200 to $600, including installation. That's quite a range!

Windows made by companies such as Anderson, Marvin, and Pella will be at the mid-to-high end of the price range. Their products have "track records," and buyers are willing to pay for reliable quality and the confidence that these companies will be around to honor their warranties, should the need arise.

Like the Pruchniewskis, you will surely find you have lower utility bills for heating and cooling once you've installed more energy-efficient windows. With our current energy crisis and rising gas and electric rates, your initial investment will soon be recouped.