The R.W. Kern Center’s Minimalist Timber Structure
Designed by Bruner/Cott & Associates and built by Wright Builders, Inc., Hampshire College’s first new building in 40 years showcases local materials and clean connections.
The R.W. Kern Center at Hampshire College in Amherst, Mass., was designed by Cambridge, Mass., firm Bruner/Cott & Associates to be “rooted in its place,” says principal Jason Jewhurst, AIA. Completed in 2016, the two-story, 17,000-square-foot building houses the school’s admissions department, classroom and gallery space, and a coffee bar. As the first new structure built on campus in more than three decades, the Kern Center is aiming high, pursuing Living Building Certification from the International Living Future Institute.
A good portion of the center’s construction materials was sourced in close proximity to the site: The schist cladding was quarried 30 miles away from Amherst; the glue-laminated timber was fabricated 60 miles north in Walpole, N.H.; and the café’s small, round tables were crafted from two mature pin oaks that were felled on campus.
“We steered ourselves toward really honest materials,” says Bruner/Cott principal Jason Forney, AIA. “So you have this palette of materials that are very much true to themselves.” Most prominent of these materials is wood. The Kern Center features a half-dozen wood species, chosen specifically to cohere within the space: black spruce for the glulam; ash and birch for the doors; salvaged red oak for the flooring and monumental stair; pine for the ceiling; and cedar for the exterior.
Materials and building systems are left exposed, inspired by the Living Building Challenge’s (LBC’s) push for material transparency. Along with wood, curtainwall glazing makes up the building envelope. “It was important that the glass felt like a veil that wrapped the wood structure. And it was okay that you could see the wood posts behind the glass,” Jewhurst says. “It was a good test for us to be minimal about the connections.”
The Kern Center features a mostly column-free glulam structure. The structure was further complicated by the architects’ goal to eliminate any unnecessary material. Instead of uniformly sized beams, Bruner/Cott worked with Montreal-based glulam supplier Nordic Structures
, local fabricator Bensonwood, and Newton, Mass.–based structural engineering firm Foley Buhl Roberts & Associates to determine the smallest possible size of each member. “We worked out a hierarchy of framing so that we could increase the overall efficiency of the yield that would need to be produced for the building,” Jewhurst says.The design team also used lightweight, 4-inch oak “car decking” for the second floor “so that the decking could support itself to the extent possible,” Jewhurst says. Beam members could then be spaced at 8 feet on center.
Equal attention was paid to simplifying connections between structural members. “We wanted this building to feel like it was of the highest quality, like fine furniture, and the detailing at those joints is where the magic has to happen,” Jewhurst says. In the second-floor classroom, for instance, 5-inch by 12-inch glulam beams neatly join an equivalent-sized rim beam and a 5-inch-square post. A 5-inch-wide steel base plate is sandwiched between the end of the beam and the face of the rim beam, with knife plates centered in both the posts and beam, secured by just two lag screws and two bolts.
Besides the mostly hidden steel plates that attach to the aluminum mullions of the curtainwall system, the only steel visible is a small seat tab below the roof beam. Jewhurst credits Bruner/Cott project architect Christopher Nielson, AIA, who was “on the phone day and night, working through how minimal we could make these connections.”
Although it was fabricated just one hour from the site, the timber for the glulam was grown in a taiga forest in northern Canada, where Nordic’s forest team selectively harvests extremely small-diameter trees. The timber is then shipped around the world, in this case to Bensonwood’s facility outside Walpole, where it was fabricated to Bruner/Cott’s specs. Although many of the beams are relatively small, some are as large as 41 feet long, 9 inches wide, and 38 inches deep, with weights creeping up to 3,700 pounds.
On-site, the novelty of the timber structure created its own challenges. According to Bensonwood structural design associate Nate Black, the company had never constructed a floor diaphragm without sheathing. To attach the deck to the glulam beams, the company used what Black describes as the “largest nail gun in our arsenal,” which can fire 5-inch-long nails.
Among the benefits of the building’s apparent structure is that it can be easily adapted or, when the time comes, disassembled. “One of the imperatives of the Living Building Challenge is net-positive waste,” Forney says. To that end, the Kern Center is designed for flexibility, so that it can be adapted as the school’s needs change—an attribute that was tested when the college abruptly chose not to relocate the campus bookstore to the Kern Center. With the building two-thirds of the way through construction, the architects redesigned the bookstore space as a ground-floor classroom. “We were able to in-frame interior glass systems that are all bolted together that fit inside the structure without making any edits,” Jewhurst says.
Forney attributes the Kern Center’s success to the dedication of the entire project team, and in particular, the general contractor Wright Builders, based in Northampton, Mass. The company’s founder and senior adviser, Jonathan Wright, is a Hampshire College alumnus and helped select Bruner/Cott. “He was deeply committed to the LBC,” Forney says of Wright, who led LBC training seminars for the subcontractors.
“Everybody was pulling in the same direction,” Jewhurst adds. “And it’s reflected in the result.”