by Zach Mortice
Associate Editor

How do you . . . design an arboretum visitor center that models the processes of natural flora and is transparent about how these processes work?

Summary: The Bernheim Arboretum Visitor Center in Clermont, Ky., is a highly sustainable facility that self-consciously and transparently models its green features after the ecological balance a tree maintains with its environment, such as producing oxygen, deriving its energy from sunlight, and itself becoming a habitat for nature. The William McDonough + Partners-designed building is made of recycled wood constructed into a series of trellises and pergolas that provides a framework to bring people into closer contact with nature.

William McDonough + Partners’ Bernheim Arboretum Visitor Center in Clermont, Ky., sits in between two noble conceptual orientations: to be a building that works like a tree and a building that explains its sustainability processes like a teacher. These goals were less an instance of formal mimicry and more an issue of building performance. The point, says McDonough’s Kevin Burke, AIA, was to ask “How productive are our buildings if we were to measure them against something like a tree?”

So how “productive” is it? The United States Green Building Council granted LEED® Platinum certification to the visitors’ center—the only building in Kentucky, Tennessee, Indiana, West Virginia, and Virginia to attain this level of certification.

Charlottesville, Va.-based McDonough + Partners, an industry-wide leader in sustainable design, explored the building as a tree and as a teacher motif previously in their Oberlin Environmental Studies Center in Oberlin, Ohio. The architect of record for the Bernheim project was Barnette Bagley Architects of Lexington, Ky.

A tree between two worlds
To enact these dual orientations, the arboretum visitor’s center had to do, or simulate, the natural ecological processes of a tree, like filtering water, creating oxygen, and using sunlight for energy. To filter water, the facility has a peat moss black water filtration system, and an 8,000-gallon underground storage cistern. A sloped parking lot prevents damaging runoff. A green roof is another of the building’s sustainability features. Both active and passive solar systems are present in the design. Photovoltaic panels generate electricity, and solar-glazed and -shaded windows moderate temperatures. The building is oriented on an east-west axis, which also moderates energy gain. The abundance of windows helps to blur the distinction between inside the building and outside amidst the evergreen and deciduous forest that surrounds it.

The most apparent sustainable feature is the building’s heavy reliance on recycled wood. It’s assembled mainly from pickle vats and bourbon rackhouse lumber. Completed in 2005, the 6,000-square-foot visitor’s center is constructed as a series of trellises and pergolas that extend out from wood-framed window walls—light, warm, and a constructive intrusion on the natural landscape. All the natural light coming through the expansive glazing makes the wood glow with an inviting golden hue, part rustic cabin and part contemporary architecture. Like a tree, the trellises themselves can become a natural habitat and a meeting place for the natural and the artificial. “The trellis becomes a sort of wrap-around shade-structure as the plants and nature grow on it,” says Burke.

Raw and natural materials fill the interiors of the visitors’ center as well and help to fulfill its other conceptual goal: to be a building that explains its sustainable features. Shagbark, hackberry, walnut, and black locust are all native Kentucky woods that make an appearance. The building’s unvarnished surfaces leave eco-friendly features out in the open to explain themselves. “We really looked at just the simplicity of the building, the framework, [and then plugged] in technology or building components in as clear a fashion as possible,” says Burke.

“The visitor center helps set the stage for storytelling about sustainability, and great stories are the bedrock of meaningful education,” says Claude Stephens, Bernheim’s education director. “The project helps illuminate the spiritual, biological, and economic advantages of living in agreement with nature.”

The Bernheim Arboretum Visitor Center sits in a 14,000-acre arboretum south of Louisville that was designed by Frederick Law Olmsted in the 1930s. Established by a German immigrant who rose to prominence through the whiskey-distilling business, the arboretum didn’t open to the public until 1950. It contains flexible exhibit space, a lobby, a shop, and a café that extends outside in good weather.

Cost vs. value
Appalachia Science in the Public Interest (a sustainable science advocacy group) reports that the Bernheim Visitor Center cost four times more than a similar standard facility. Burke says his firm and this project’s client weren’t concerned with energy savings payback schedules and strict cost-benefit arithmetic. Instead, Bernheim was more interested in a holistic view of its new visitors’ center, one that centered on cost vs. total value, not cost vs. payback. Burke says this type of client is often the most amenable to green and sustainable building practices. “What’s interesting is to engage with a new culture and see how they interpret these types of frameworks.”