A Look at Trends in Window Design
by John Stephenson
Technology continues to change the window industry. Advancements in frame manufacturing
and the development of new glazing materials have increased the variety of window products
available in today’s marketplace. Technology, such as the Internet, has provided
increased knowledge for consumers who now have instant access to a wealth of window
information before they make a purchase. However, all these options can make window
selection seem like a complicated task.
Consumers need a reliable source to turn to — a glass manufacturer, window
fabricator, distributor or retailer — someone who can sort out the information,
clearly explain product differences and match the best product to their individual needs
and desires. As you know, a window “perfect” for one application may not be
suitable for another. Several factors must be considered before choosing a frame and
glazing option. These include: climate, weather conditions, amount of sun exposure,
aesthetic preferences and lighting, heating and cooling requirements. To make a
fully-informed decision, your customers must understand the benefits different window and
glazing components provide and under which conditions they perform most effectively.
Because consumers have easier access to information than they did years ago, you will
likely find yourself facing more in-depth questions about products. Following is an update
on some of the most recent industry developments.
For many years wood (such as this woodclad bay window from Milgard) was
the most popular window frame material.
Vinyl Volume
For many years, wood was the most popular window frame material. In 1991,
wood held 48 percent of the market share, whereas vinyl represented just 25 percent,
according to the Window and Door Manufacturers Association (WDMA). Last year, for the
first time in history, vinyl surpassed wood as the market leader. From 1991 to 1998,
vinyl’s market share increased 18 percent, with vinyl commanding 43 percent of the
market by year’s end. This rising trend is forecasted to continue, according to the
WDMA. The association estimates 23.4 million vinyl windows will be produced in 1999
(representing 44 percent market share), compared with 21.3 million wood windows (40
percent market share).
New processing techniques and the use of different vinyl compounds have improved the
performance and appearance of vinyl window products and enhanced their popularity.
Vinyl’s durability, low maintenance and energy-efficient nature make it a popular
choice today.
Vinyl windows from Milgard.
New Wood Looks
Although no longer the market leader, wood windows remain in high demand.
Wood has long been cherished for its inherent beauty and insulating qualities. Traditional
wood frames have low U-values and withstand extreme temperatures. But, unlike vinyl, wood
windows require regular painting and maintenance. If wood frames are not protected
properly from moisture, they can warp and crack.
To address these concerns, some manufacturers now offer special composite frame materials
that minimize the need for maintenance. Generally these composite products have high
insulating values and exceptional durability. For example, our company manufactures a
Wood-Clad™ line constructed of fiberglass on the outside
and vertical grain Douglas fir on the inside. Fiberglass provides the look of painted
wood, without the maintenance. It withstands ex-treme temperatures and resists moisture
and corrosion. It is also an excellent insulator, with very low U-values. Fiberglass
frames do not warp, shrink, swell or rot. On the inside, vertical grain Douglas fir
provides energy efficiency, while offering the fine detail and genuine beauty of wood.
This type of wood is prized for its ability to resist dents and scratches. It also accepts
stains with consistency and ease. Composites such as WoodClad keep the wood on the inside
where there is less exposure to harsh elements, reducing the need for maintenance and
protecting and preserving the wood’s natural beauty.
Bigger Views
Aluminum windows are making a comeback. They are structurally rigid,
allowing for less frame and more glazing area than vinyl. Aluminum windows with large
glazing areas are particularly popular in homes where view is paramount. They commonly are
used with a clear anodized finish in high-end, contemporary custom homes where less focus
is placed on the window itself. Low maintenance is one of the benefits of aluminum
windows. Aluminum doesn’t rot, peel or require painting. Special glazing options can
be added to aluminum windows to enhance energy efficiency and increase comfort.
Glass Options
Once a frame type has been selected, glass is the next consideration. Does
your customer have concerns about energy efficiency or comfort? Perhaps you should
recommend an insulating glass unit with a low-emissivity (low-E) coating. Low-E coatings
reduce the amount of heat a window radiates, thus improving a window’s energy
efficiency.
Another attraction of low-E is its ability to usher in visible sunlight, while blocking
most infrared and ultraviolet (UV) rays that can cause fading of interior carpets and
furniture fabrics.
At one time, low-E glass was recommended primarily for cold climates. But now
manufacturers have introduced a new generation of products called low-E2 which also work
effectively in warm climates. As a comparison, standard low-E glass reduces ultraviolet
rays up to 54 percent, whereas low-E2 can decrease ultraviolet rays up to 85 percent.
Tinted glass is also effective in warm climates. It minimizes the amount of solar heat
that enters a home and reduces uv light damage. It also adds an element of privacy by
decreasing visibility to the interior of a home.
Warm-Edge Technology
Condensation is a common complaint among homeowners. In a typical window,
the thermal resistance around the edge is lower than that in the center. Heat can escape,
making the window susceptible to condensation. To combat this problem, manufacturers have
made advancements in warm-edge technology.
In an insulating glass (IG) unit, the layers of glazing are held apart by spacers. Air
currents between the panes of glass carry heat to the top of the unit, while cold air
settles at the bottom. Filling the space with a slow-moving, low-conductive gas such as
argon, is one way to reduce the amount of heat transfer that occurs between the inside and
outside of the unit. Argon is heavier than air, which slows the rate of heat transfer.
The spacer it-self also can affect a window’s ener-gy performance. Traditionally,
spacers were constructed of four sides of aluminum. Aluminum was not highly effective,
however, because it conducts heat. In other words, heat was able to escape through the
edges of the window, causing energy loss and condensation. A more recent approach utilizes
a U-shaped steel spacer. Steel transfers less heat than aluminum, thereby increasing
energy efficiency. The U-shape means only a small percentage of the steel touches the air
space. The remaining space is filled with butyl, an elasticized adhesive. The U-spacer
also absorbs much of the glass movement that can occur when temperatures fluctuate,
reducing the chance of seal failure and glass breakage.
Window Savvy
Whether it’s warm-edge technology, glazing or framing options,
manufacturers continue to develop new and improved products. Keeping up-to-date on these
advancements will increase your credibility with consumers. They will know they can count
on you as a reliable source for window information, which may lead to referrals and future
business for you. To provide the best advice and service to your customers, find out about
the surrounding conditions where the windows will be installed. Will they be in direct
sunlight with no overhang protection, or in the shade? What is the climate like? What
factors is your customer most concerned with—appearance, maintenance, energy
efficiency, cost?
Every application is unique, and your recommendation should be based on each
customer’s individual needs and desires. Emphasize the benefits and features that
different products offer. For example, many people choose wood for its flexibility in
staining or painting, energy efficiency or for aesthetic
reasons. Vinyl is a good choice if your customer wants low maintenance. If budget is a
concern, aluminum is a cost-effective alternative. Special glazing options such as low-E
coatings, can enhance thermal efficiency and protect interiors from damage caused by UV
rays. Perhaps you can recommend mixing two types of windows, depending on the exposure the
home faces. Composites, such as WoodClad, may be a good solution for someone who wants the
natural beauty of wood, without the worries of maintenance. Whatever the case, taking a
few extra moments to provide personalized service will pay off in the long-run.
John Stephenson is marketing manager for Milgard Windows, based in Tacoma, WA.
USG
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