[ BUILDING GREEN ]
Cutting-edge Timber Technology
A new breed of building appeared on the UMass campus in Amherst this
past winter. In a landscape full of concrete, brick, and stone rose a four-story
wooden frame, fitted together like a piece of Ikea furniture.
It’s an architectural anomaly, yes, but the 86,000-square-foot Design
Center’s true distinction is its contribution to softening climate change. Wood
that’s harvested sustainably has a substantially smaller carbon footprint
than steel or concrete, and carbon that would otherwise be released into the
atmosphere when a tree dies is sequestered in finished wood products. As
such, architects estimate that this building offsets carbon in the atmosphere
by roughly the same amount in a year as taking 500 cars off the road.
“The building is basically a carbon storage tank. . . . Wood is the original
carbon fiber,” said Peggi Clouston, a wood mechanics professor at UMass
and a driving force behind the project. The Design Center is the second building of its kind in New England.
Suddenly, wood construction has gone from quaint to cutting-edge.
The new technology – called cross-laminated timber, or CLT – is exciting
architects, woods-economy boosters, and sustainable-forestry advocates.
Architects and engineers worldwide are racing to see who can build the
tallest wooden structure. The current record holder is a 14-story apartment
building in Bergen, Norway, but a 24-story building is going up in Austria.
Last September, the U.S. Tall Wood Building Prize Competition awarded its
first $3 million prize, which was shared between a 10-story building in New
York City and a 12-story building in Portland, Oregon.
Closer to home, the University of Maine is hustling to complete testing of a
hybrid engineered wood panel that officials hope will be well-positioned to capture business in the East Coast construction industry. (The panels used at UMass
came from Chibougamau, Quebec, nearly 700 miles and a country away.)
Cross-laminated timber technology was developed in Switzerland and
refined in Austria during the 1990s. The material is essentially supersized
plywood made of crisscrossed layers of dimensional lumber. It’s strong
enough to serve as a structural element and can be delivered to jobsites with
window openings and fastener holes precut; speed of construction is one of
CLT’s selling points for builders.
But it’s the carbon-storage capacity that gives CLT its sex appeal. Trees
breathe in atmospheric carbon as they grow, storing it in roots, branches,
and trunks; if harvested for timber, the carbon then stays locked up in long-
lived products like furniture and buildings. “It’s a very compelling story,” said
Clouston – particularly with architects, who are early decisionmakers in the
choice of building materials. “It’s better for the environment, but that isn’t the
whole story. Money speaks.”
The introduction cost of CLT was nearly its undoing. Informed by her
roots in British Columbia and her three-decade career in wood engineering,
Clouston had advocated for a wooden building at UMass for years. But a cost
comparison with steel-frame construction jeopardized the wood option until
it was rescued by an additional $3 million secured by then-Congressman
John Olver. The extra millions were justified as necessary to cover the added
costs of introducing a new building technology: the code-variance requests,
supply-chain challenges, and caution and inexperience at all levels.
The Design Center helps to showcase CLT technology through the intentional visibility of wood in the design. “It’s a demonstration structure, so everything
is exposed,” Clouston said. “Being in this building is going to be a completely
different experience. . . . Wood really feels different.” One goal of the project
was to spread the word about CLT: a plethora of photos, text, and videos on
the UMass website help to document the building material and process, and
the building’s story is being told by those who know it best, including Boston-based architecture firm Leers Weinzapfel Associates and Suffolk Construction,
Boston’s largest building construction company. The departments occupying
the new space include, appropriately, Building and Construction Technology,
Architecture, and Landscape Architecture and Regional Planning. For her part,
Clouston speaks at conferences on the topic as often as she can.
“We’re trying to have a ripple effect,” she said. “We’re trying to talk to
people who can make a difference: architects and engineers.”
The prospect of growing demand for these high-tech wooden buildings
has some folks in Maine talking of opening a CLT manufacturing plant in the
state, which desperately needs new forest products industry jobs given the