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 Going
Green with Glass in Arkansas
 The
Arkansas Department of Environmental Quality's (ADEQ) mission is
to protect, enhance and restore the environment, so when designing
its new headquarters, the group wanted a building that reflected
its green goals-in a functional, practical and affordable design.
When the state outlined its plan to become the first green state-owned
office building in Arkansas to architects at Little Rock's Taggart
Foster Currence Gray (TFCG) Architects, the design team immediately
thought of glass.
"Our concept was to create a narrow building with as much glass
as possible," says Jerry Currence, principal in charge of design
at TFCG. "Using glass, we could introduce as much daylight
as possible and offer views of the nearby river and mountains."
Although daylighting was important, the six-floor, 124,310-square-foot
building also needed to be energy efficient to attain the LEED certification
it desired.
This meant consulting with the team at glass fabricator Viracon.
"The key to successfully using glass for daylighting is to
combine the glass with one or more high-performance coatings that
can control and direct the light and reduce solar heat transmission,"
says Don  McCann,
manager of architectural design for the glass supplier.
The structure's insulating glass curtainwall consists of 35,216
square feet of glass featuring VRE-38 coating on the #2 surface
of a green substrate in both vision and spandrel areas. A radiant
low-E coating, VRE-38 provides a neutral exterior color and allows
two-way vision under varying light conditions. It has a 30 percent
light transmission level, and solar heat gain coefficient of .19
for an interior reflectance of 21 percent.
The green glass substrate also enhances the solar performance of
the glass while enhancing building aesthetics. "We chose green
glass because we were building in a very natural environment, and
the green glass enhances the green of the trees and other natural
colors," says Currence.
To further enhance solar performance, Currence and his team designed
a unique configuration of vision and spandrel areas. On each floor,
from the main viewing area to the ceiling, the glass is transparent
and has only the VRE coating. On the lower glass area down to the
floor, the glass incorporates a simulated sandblast ceramic frit
in combination with the VRE coating.
 "This
configuration has two benefits," says Currence. "All circulation
is on the exterior wall of the building, so having a translucent
look at the bottom gives the perception of security to people who
may be uncomfortable walking next to the wall of glass. It also
allows diffused natural light into the building but blocks solar
heat in areas in which we don't necessarily need a clear view."
Ceilings in the building are level throughout the workspace, then
slope up to form a knife edge where the ceiling meets the curtainwall.
The ceiling is painted white, which allows light entering the upper
windows to reflect into the workspace. Horizontal solar shades on
the south side of the building also help bounce light deep into
the building's interior.
The ADEQ building earned LEED Gold certification and three Green
Globes from the Green Building Initiative. It is the first LEED-Green
Globe dual certified building in Arkansas.
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