Designing a green building—particularly one with several different uses and a natural ventilation system—can be challenging. When one of those uses is to house a university architecture program, the pressure to innovate in both form and function is heightened.
Judson University in Elgin, Ill., chose architectural firm Short & Associates, Stamford, U.K., in a design competition, in part because of Short’s experience with natural ventilation systems in the U.K. British designer C. Alan Short says knowing that Judson University’s Harm A. Weber Building would be full of professors and students analyzing the design was a little intimidating, but the biggest challenge was to create a “practical, super low-energy building in a cruel continental climate.”
Natural Ventilation
Credit: Bruce Starrenburg - (c)2009 Bruc
Unlike Short’s natural ventilation projects in the U.K., the temperature fluctuations in Illinois—as well as the humidity control requirements of the library portion of the building —required a hybrid natural/mechanically assisted system model. According to Short, a number of scientists at the University Cambridge, Cambridge, U.K., helped invent the system. It can flip between naturally ventilated and mechanically assisted modes, reducing energy consumption by at least half without any loss of comfort. “[The system] has a dense inner core of concrete to stabilize temperatures and wraps a lighter weight metal-framed, metal-clad skin around the concrete core to make a deep wall,” explains Short.
In addition to the mixed-mode natural ventilation system, the building has natural daylighting, solar photovoltaics and a landscaped stormwater system. It houses the Benjamin P. Browne Library, large ancillary spaces and mechanical rooms, the University’s fledgling School of Art, Design, and Architecture and studio/classroom space. The 4-story, 88,000-square-foot (8175-m2) building received LEED Gold certification from the Washington, D.C.-based U.S. Green Building Council.
Short designed the building in three blocks: a rectangular library/studio portion wrapped around a central atrium, a long rectangular Art & Design Building that the architect and university refer to as being “bar shaped,” and a bow-tie shaped block connecting the two, which holds studios and classrooms. According to Short, the rectangular shape that houses the library gave the librarians the most flexibility, while the classrooms and gallery space worked well in the more unusually shaped wings of the design.
The building is constructed mostly of concrete for its thermal mass qualities. Many interior walls are exposed to radiate either warmth or coolness, depending on the season. Metal-clad exterior walls sit about 4 feet (1.2 m) away from the concrete building, creating a space that is used for the natural ventilation. “You can couple lightweight metal structures and skin with heavy construction somewhere in the building, maybe below ground, to deliver a very resilient, stable, comfortable environment,” says Short.
Short’s plan allows the space between the inset windows to be used to create an open shaft that utilizes the natural tendency of buoyant warm air to rise. This creates a natural vacuum, which draws cool air in at the bottom, circulates it and exhausts it through rooftop ventilators. Air on each floor is drawn laterally by the upward pressure of the stacks. The air cavity between the concrete core and the metal-clad exterior walls is used as a chase space for the vertical air flow in the natural ventilation system, and to cut some of the direct solar gain.
“The building was a creative masterpiece of integrating multiple academic programs with the campus information center,” says Professor Keelan Kaiser, chair of Judson’s Department of Architecture. The School of Architecture has hosted a number of professional societies and 12 professional juried papers already have been written about the project. “Plus, compositionally, it’s just a beautiful building,” he adds.
Art and Craftsmanship
“The design is a contemporary approach to the arts and crafts style, which fits well with the surrounding restored prairie landscaping,” Kaiser explains. The original design called for wood shingle siding, but for a variety of reasons, including maintenance and fire safety, metal panel siding was chosen instead. “It uses a large-scale shingle approach,” he says. “The shingle-like panels cover all the areas on the exterior where there is natural ventilation ductwork. It’s a visual marker of the natural ventilation chases, which are important features of the design.”
The copper penny-colored Kynar coating is “very pretty, especially at dawn and sunset,” says Short. “And the elevations are facetted so the sunlight tracks around them.”
Wiesbrook Sheet Metal, Plainfield, Ill., spent more than 1,700 hours on shop prep and more than 12,000 hours doing on-site installation. Every roof and wall panel on the three wings of the building was a custom cut and fit. Every wall panel was custom fabricated.
“It was a huge job,” says Ken Wiesbrook, vice president of Wiesbrook Sheet Metal. “I probably made it harder on us than it needed to be; we used no corner posts on the job. All the corners were measured, notched and bent. It would have been much faster to use posts and trim, but aesthetically and from a maintenance standpoint, this was better. Lining all that up over such a huge building was a challenge, though.”
According to Wiesbrook, metal window wells and louvers also had to be custom fabricated and “all those goofy jut-outs and air-exchange plenums had to maneuvered around.” The on-site portion of the job took about 14 months and involved 8 to 10 installers at any given time.
The custom details were the most time-consuming part of the job. “Basically, this was a no-exposed fasteners job,” says Wiesbrook. But the intricate detailing had a silver lining for the Weisbrook installers. “Once in a while, you get a chance to show your colors, so to speak,” Wiesbrook admits. “This job gave our installers a chance to really show their craftsmanship.”
Lisa Anderson Mann writes about architecture and metal construction from Petaluma, Calif.