Green and Graceful
Paul Deffenbaugh, Editorial Director,
Posted
08/07/2012
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.
