What if a building could act like a tree? That question intrigued William McDonough, FAIA, as he embarked on an assignment nearly 16 years ago to design a living structure “that produces oxygen, sequesters carbon, fixes nitrogen, is photosynthetic, accrues solar energy as fuel, makes complex sugars and food, changes colors with the seasons, creates microclimates, and self-replicates while purifying water,” he recalls.

McDonough, founder of William McDonough + Partners, was inspired by Le Corbusier’s idea of a house as a “machine for living.” We could then move to the next question, which would be: What if a building could be a living thing?” he says. “And if it was, what would it mean to design in support of nature, what principles would we need to operate under?” Together with David Orr, the Paul Sears distinguished professor of environmental studies and politics at Oberlin College in Oberlin, Ohio, McDonough realized his vision in January 2001 with the opening of the Adam Joseph Lewis Center for Environmental Studies (AJLC). It was declared one of the 30 milestone buildings of the 20th century by the U.S. Department of Energy (DOE), and was a 2002 AIA COTE Top Ten Green Project.

Conceived as a demonstration project and educational venue, the AJLC’s design would also serve as a catalyst for the emerging field of sustainable design. Planning for the center began in 1995, after Orr came to Oberlin College as its environmental studies chair. His first priority: to establish a new facility for the program. The final result would take a change in the school’s administration and would require a multimillion dollar fundraising effort, yet Orr’s original design intent became clear: to construct a new building that was “deeply instructive.”

First, Orr assembled a design team comprising experts in education, architecture, renewable energy, and current technologiesincluding William McDonough + Partners in Charlottesville, Va., as design architect and Philadelphia-based Andropogon Associates as landscape architect. In large part, this supported Orr’s driving principle of ecological design, envisioning the new center as an integrated building-landscape system orchestrated to change and improve in performance over time. That process also became an educational venture, featuring 13 public design charrettes that served to solicit community, faculty, and student ideas for the building’s program and performance. “We realized people needed something really special to inspire them into a new design framework,” McDonough recalls.

After 10 years in operation, the Lewis Center has served as a source of inspiration as a net-energy exporter, powered by sunlight, generating zero discharge. The 13,700-square-foot building highlights a range of energy-efficient features now considerably more common, such as passive solar design, natural lighting, high-efficiency electrical lighting, natural ventilation, energy-recovery ventilation, an enhanced thermal envelope, integrated thermal mass, recycled materials throughout, and a ground-source heat pump system. A constructed wetland and 7,500-gallon rainwater cistern manage all stormwater on-site. An indoor, solar aquatic Living Machine processes all of the building’s wastewater. Occupants control heating and cooling in offices, while a combination of occupancy, CO2, and lighting sensors ensure comfort in classrooms.

Since its completion, the Lewis Center has grown in size and scope. To capture high-resolution data for research, ongoing commissioning, and education, Oberlin partnered with the DOE’s National Renewable Energy Laboratory to install 150 environmental sensors throughout the building and landscape. This data-monitoring system provides real-time feedback on the performance of solar arrays, energy consumption by each of the major end-uses within the building, weather conditions, soil temperature and moisture, on-site rainwater storage, biological activity, and the flow of water within the on-site wetland-wastewater treatment system. In turn, a building dashboard in the lobby displays the data in a format designed for a nontechnical audience (see oberlin.edu/ajlc).

In June 2006, a second 8,800-square-foot photovoltaic array was added over the parking lot and, when combined with an existing 4,800-square-foot, 60kW array, increased the site’s energy production by 100kW. The on-site Living Machine continues to perform a vital pedagogical role for students, who set up, monitor, and maintain the system while researching issues of wastewater, wetland ecology, microbiology, and plant dynamics. Meanwhile, the daylit, naturally ventilated atrium became a social center on campuseven a place for weddings. “All of a sudden the building, this little sapling of an idea, became very popular with students,” McDonough says. “It was occupied 24/7 and remained open in summer, which they never expected. Fascinating in terms of practice … is that buildings change. That’s the point, they grow.”

Orr now reflects on the success of the Lewis Center, after 10 years as an educational facility, in helping to launch the campus green building movement. “For me,” he says, “it was proof of concept, that you could do design at that full spectrum scale, and you could also make design deeply educational for the community.” Growing directly out of the building’s success is yet another initiative, the Oberlin Project, a joint venture between the city and college to create a model of “full spectrum sustainability” for Oberlin’s downtown set to launch during 2011. “What I’m most proud of is the effect the building had on Oberlin students,” Orr says. “It really did change lives: kids could see solutions to problems in built environments. I don’t know what we’re doing with global warming at the global scale, but we know what to do with it at the building scale, and now we’re taking that up to the scale of a small city.”

David R. Macaulay is the author of Integrated Design: Mithun, The Ecological Engineer, and the blog Green ArchiTEXT, greenarchitext.com. Read a companion Q&A with David Orr.