Hot, hazy summer evenings and fireflies. Savory hushpuppies and barbecued chicken. Long, thin buildings and porches. Those words speak to the unique culture, environment and architecture of North Carolina. The new AIA NC Center for Architecture and Design in Raleigh, N.C., uses the language of design to express the same cultural iconography. This building belongs in North Carolina, and through its use of sustainable building practices-such as its zinc standing seam roof-it also articulates a clearly defined future for architecture in the state.
The North Carolina Chapter of the American Institute of Architects had outgrown its long-time headquarters in the Water Tower and determined a new facility was needed. To select a designer among the hundreds of members required an open competition in 2008, which was won by noted green architect Frank Harmon, FAIA, founder of Frank Harmon Architect PA, Raleigh. His design reflected the best of North Carolina and aimed to be an example for sustainability that could be mimicked across the state.
A Roofing Imperative
A key element of the design and its sustainability bona fides is the 20,000-square-foot VMZINC double lock standing seam roof from Raleigh-based Umicore Building Products USA Inc. The red PRIGMENTO zinc coating gives the building an earthy feel while offering enough texture and depth to provide interest on the north elevation where the roof runs down nearly to street level. There it’s interrupted by a balcony-like ledge that captures the rain runoff and redirects it. Harmon says of the roof, “It’s made of real materials.”
That honesty of expression bolsters the roof’s sustainability quotient as well. Because zinc requires little energy to manufacture, provides a roof that is durable (lasting 80 to 100 years) and utilizes 100 percent recyclable materials, it gains high points in the United States Green Building Council’s (USGBC) LEED certification process.
The building was designed to achieve LEED Platinum status and likely will when photovoltaic panels are added to the roof, which is ideally sloped to capture maximum solar exposure. But roofs do more than offer aesthetic interest and provide platforms for solar panels. They collect rainwater, and this one funnels the rain through a 12-inch downspout, where it is captured in a collection pool, and then spilled into a bio-retention sill that filters the water back into the ground.
“When I was a kid,” says Harmon, “you could swim the streams around North Carolina. Now they’re filled with mud and silt.” By keeping the water runoff on-site and out of the sewerage, the design prevents the further contamination of streams.
Location, Location, Location
To set an example of sustainable design for the state, the building needed an appropriate platform. The AIA of North Carolina achieved that by securing a site near the state capitol and other state offices. The shape of the site-trapezoidal and on a sloping lot-became a defining element of the building design. Harmon positioned the building toward one end of the lot, accentuating the front porch aspect of the design created by the 12-foot overhang. The roof overhang protects the cypress-covered south-facing elevation from the summer sun, but allows the winter sun to penetrate and light the interior. A green screen fabricated by SteelFab, Charlotte, N.C., will support vegetation that also will shade the building.
Allowing the light to penetrate the interior and creating an open interior space offers a working environment that doesn’t require artificial lighting. The predominantly southern breezes can be captured and help cool the space because windows on opposite sides of the building are located in such a way to support cross breezes. Geothermal heat pumps (buried beneath the porous pavers in the car park) provide supplemental heating and cooling.
For any office space, the success is in the acceptance of its occupants. Many state agencies have discovered what a desirable facility the building is, and rent its rooms for meetings and other public gatherings.
