It's not easy to design a handsome building, no matter what its type. You have to get so many elements just right if you want it to rise above the mediocre or mundane. You have to nail the usual to-do list of massing, scale, proportion, and detail. But great buildings usually have another thing going for them too: a great skin. The best ones are clad in an attractive material, with details resolved in a skillful, nuanced way. Says Sebastian Schmaling, AIA, principal of Milwaukee-based Johnsen Schmaling Architects, “It's the dress of the building—the thing people see first; the thing they want to touch.”

A few years ago, this magazine examined intriguing new cladding specs gaining traction—Cor-Ten steel and Parklex among them—and some evergreens (copper and zinc, for example) making a comeback. Today, new options are emerging faster than it takes the ink to dry on your construction drawings. Figuring out which options will endure takes diligence, patience, and ingenuity.

clad tidings

For firms like Johnsen Schmaling, cladding provides an opportunity to explore the possibilities of what structure can be. “We sometimes work backwards,” Schmaling admits. “We have an image of the building in mind and then find something to match. We have some of the craziest ideas of what we want to put on the building, but then we get a reality check.”

Reality check notwithstanding, Johnsen Schmaling will often consider unusual or unlikely materials, such as CYRO Industries' Acrylite translucent acrylic sheets. “We wanted to use it as cladding on a small house” and backlight it “to create a glowing cube,” Schmaling explains. “But the product moves a lot, so it's hard to control the joints” when it's used as siding. One material the firm has had luck with is Baq+—a high-density resin panel faced with natural wood. According to Prodema, its Spanish manufacturer, Baq+ is coated with an acrylic finish to stand up to harsh environments. Each panel measures 96 inches by 48 inches and comes in five colors.

Architect Sebastian Mariscal, principal of an eponymous studio in San Diego, also spends a fair amount of time researching materials for his buildings, and he's particular in what he expects from them. “For me,” he says, “the skin has to be light. I don't believe in heavy or wet skin, like stucco. It should be thin, lightweight, and dry.”

Mariscal's search has led him to such modern classics as wood, stainless steel, and Cor-Ten, but his new favorite comes from GranitiFiandre, an Italian manufacturer with a U.S. office in Itasca, Ill. Produced as part of the company's Geologica series, NewStone engineered stone is thin, lightweight, and strong, says Mariscal. The tiles come in sizes measuring 12 inches by 24 inches and 12 inches and 24 inches square.

Other architects opt for more familiar materials but put a new spin on them to update their looks. Jill Bouratoglou, RA, and her husband, John, wanted fiber-cement siding on their Brooklyn, N.Y., home, so they clad it with 4-foot-by-8-foot Cembonit panels. “We wanted some masonry to fit the neighborhood,” Jill explains, “but we're modernists, so we opted for the [large] cement boards. They're lightweight and durable and allowed us to layer the building with traditional brick.” Louisville, Ky.-based Cement Board Fabricators manufactures Cembonit in eight prefinished colors (including granite, jade, and pearl) in sheets as large as 4 feet by 10 feet.

A recent entry in the exterior cladding market is PaperStone XP rainscreen cladding from Hoquiam, Wash.-based KlipTech Bio Composites, which manufactures paper-based countertop surfacing of the same name. According to company founder and vice president Joel Klippert, the FSC-certified cladding is made from up to 100 percent postconsumer recycled paper, contains an aluminum oxide for durability, and has a UV inhibitor to prevent fading. It can be machined and installed like wood in 4-foot and 5-foot widths; 8-foot, 10-foot, and 12-foot lengths; and thicknesses of 3/8 inch or ½ inch. Thirteen colors, including denim and slate black, are available.

One product on the rise here in the United States actually originated in the Netherlands. Trespa International's Meteon is a decorative exterior cladding made from thermosetting resins reinforced with wood fiber and laminated under high pressure and heat. The moisture- and UV-resistant panels are particularly well-suited for rainscreen applications, the company says. Panels can be speced in three standard sizes (60 inches by 120 inches, 73 inches by 100 inches, and 73 inches by 143 inches) and thicknesses of up to ½ inch. Color options are extensive, because the material can be manufactured in dark and light neutrals, midtones, wood décors, and even metallics.

Indianapolis-based Citadel Architectural Products also manufactures a metallic cladding suitable for exterior applications. Panel 15 is a prefinished composite panel comprised of a textured aluminum skin laminated to Douglas fir exterior-grade plywood. A fiberglass-reinforced kraft/foil scrim backer steadies the panel and acts as a moisture barrier. Panel 15 comes in a variety of texture finishes and sizes of up to 5 feet by 10 feet.

Yet another option is true stainless steel from Millennium Tiles in Elkhorn, Wis. The company's 15-inch-by-9 1/8-inch corrosion-resistant tiles are constructed from 75 percent recycled materials and are protected by a 50-year warranty. They can be produced in their natural color state or subjected to a special process that creates permanently chip-, fade-, and peel-resistant finishes, including amber bronze, slate, and custom colors.

In some cases, exciting new options are right in plain sight. When Steven Ehrlich, FAIA, was designing his house in the Los Angeles area, he wanted to clad it in something unique. “One of the hopes I had was that the materials would not need maintenance, coatings, or paint and would not need to be resurfaced,” the Culver City, Calif.-based architect says. His search led him to Cor-Ten steel and an unlikely option: Trex composite decking from Winchester, Va.-based Trex Co. “It's made from recycled plastic and wood, so it's sustainable,” Ehrlich says. “It won't need paint or oil, and there are no splinters.” He also appreciates the fact that the material will fade slightly over time. “I like products where I can see the process of weathering,” he says.

thorns in your siding

Having an opportunity to use alternative materials is exciting, but such explorations and experimentations come with caveats. “Cost is often the big driver,” says Terry A. Willis, AIA, a senior associate at Denver-based 4240 Architecture. “But context is huge too. We [prefer] to design buildings that fit the area, so we often can't use the materials we'd like.”

Although his firm investigates all the hip materials, Willis says it's important for architects to consider how a material will hold up in a project's regional climate before specing something unconventional. “With our harsh sun and high freeze-thaw cycles, materials undergo a lot of stress,” he warns.

Of course, it's also important to ensure that the sheathing underneath is just as sturdy as the cladding that conceals it. After all, when it comes to great design, beauty isn't merely skin deep.