all systems go
Glass and shading solutions might be a tad too conservative for some architects, especially those who enjoy combing the commercial world for alternatives. Sander did just that when designing the street-facing volume on his own house.
“The large wall of [that volume] faces east, so I wanted light but not direct light,” he explains. Clear glass was too expensive, and other options didn't suit the application, so the principal of Sander Architects chose 4-foot-by-24-foot opaque Deglas Heatstop panels from Degussa Röhm CYRO instead. According to the manufacturer, the ½-inch-thick extruded acrylic sheets are impact- and shatter-resistant and have a rigid design that can withstand live loads. They're also said to be energy-efficient, lightweight, and inexpensive. “They were half the cost of glass,” Sander confirms.
Canton, Mich.-based Duo-Gard Industries makes comparable vertical glazing systems that can be used in exterior walls. One such product is PCSS, a new generation of polycarbonate structured sheets that balance light transmission and energy efficiency. Suitable for windows, skylights, walls, and clerestories, the multiwall glazing system reportedly weighs one-sixth as much as traditional glass and has 200 times the impact strength, enabling architects to work with wider spans and lighter supports. It's also about one-third to half as pricey as glass or fiberglass.
Because he works in and around the nation's capital, Alexandria, Va.-based Robert M. Gurney, FAIA, often encounters historic row houses and long, narrow spaces. To bring natural light into the homes he designs, he relies on structural composite sandwich panels from Kalwall Corp. in Manchester, N.H. The architect calls Kalwall “a great material,” noting that it's “particularly useful in townhouses.”
Its manufacturer describes Kalwall as a translucent wall system formed by permanently bonding fiberglass-reinforced faces to a grid constructed of interlocked, structural aluminum, thermally broken I-beams. Said to be both lightweight and strong, Kalwall features fiberglass insulation between its sheets, making it a potentially effective controller of solar heat gain. Each 2 ¾-inch-thick panel measures up to 5 feet by 20 feet and is available in a variety of finishes. (Other makers of lightweight, translucent walls include Advanced Glazing Systems in Burnaby, British Columbia; CPI International of Lake Forest, Ill.; Janesville, Wis.-based Gallina; and Polygal in Charlotte, N.C.)
Architects unconstrained by budget limitations often turn to European structural glazing systems, such as LINIT channel glass by Lamberts. Distributed by Bendheim Wall Systems of Passaic, N.J., LINIT can be speced to heights of up to 23 feet—without structural framing members. Profilit, a self-supporting glazing system from Pilkington Building Products in Toledo, Ohio, is yet another option.
Given the range of choices, it's especially important to weigh the pros and cons of each solution carefully. Energy efficiency considerations will vary depending on the project's geographic location, for example, and widely ranging structural capacities will make some products more suitable than others in certain situations. It's also a good idea to investigate the client's security needs, since impact strength varies by system.
Once you've done your homework, your only limitation might be your imagination. If speced well, alternative glazing solutions can deliver spaces that are light years ahead of more conventional options—and a great frustration to nosy neighbors everywhere.
advanced glazing systems
bendheim wall systems
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pilkington building products