By Jeff Gersh, Communications, Washington State Forest Carbon Work Group, jeff@narrativelab.com
“We’re disrupting the building industry and moving to a bio-based economy.”
–Susan Jones, Architect, atelierjones
Before she became a global pioneer in the design of wooden buildings, Seattle architect Susan Jones was a forest nymph. As a seventh grader, she walked a mile-long path of trees to school each day.
“It sounds like a cliché, but seeing the light filter through that canopy of green and how it changed with weather and time was pretty extraordinary for me,” she said.
Her curiosity about construction arrived early. At age five, Susan watched from a homemade cedar swing as her parents built a wood house in Bellingham, Washington. “I was wonder-eyed about the whole thing,” she recalled.
During a field trip with her grandfather to a newly purchased 160 acres on Orcas Island, she strolled with him among freshly planted white pine and fir no bigger than she was. “When you’re my age,” he told her back then, “all these trees will be ready to harvest.”
After a generation of inattention, it has become a place of discoveries.
“Our family forest opened the doors for me to understand the challenges of forest management, as well as the beauty and the regenerative aspects of that process,” said Susan. “And, it has enlarged and deepened my whole experience of building with mass timber.”
Mass timber, or engineered wood, is a family of precision-fabricated, load-bearing building materials including beams, columns, walls, floors, and roofs. Susan is especially intrigued with cross-laminated timber (CLT), a game-changing technology for construction. Made from dimensional lumber—like 2x4s—sandwiched together at right angles, these components can be delivered in mammoth sizes much like tilt-up concrete walls; 12 x 60 feet is not uncommon. Some people refer to them as “plywood on steroids.”
However, this is not your grandmother’s plywood.
“Wood, being a natural material, comes with variations; that’s what gives it character, but variations can introduce weak spots,” Susan said. “By combining and optimizing many small pieces together, mass timber offers lighter weight and great strength, comparable to concrete and steel—but without having to cut large trees.”
While CLT was invented in Europe and has been part of its building culture for decades, the product is relatively new in the U.S. Susan built her family’s home with cross laminated timber in 2015, followed by a string of commissions showcasing its possibilities.
“I used to joke that my firm, atelierjones, had more CLT projects than any other architect in the country,” she said.
At that time, the architecture and engineering professions were focused on saving “operational carbon” by installing triple-glazed windows, for example, or solar panels. “The question became how to lower embodied carbon by substituting for concrete and steel, the twin wonders of modernist architecture and of 20th century construction,” Susan said. (The “twins” are the source of over 20 percent of global CO2 emissions.)
For architects and builders, one of the biggest hurdles to progress was bureaucracy. Building codes in the U.S. prevented using mass timber in structures higher than six stories. Susan accepted an invitation from the American Institute of Architecture to join an ambitious, multi-year, pro-bono effort to rewrite the national building code. Many studies ensued, but one focus was on the obvious question of fire safety. It turns out, another attribute of mass timber is its stubborn resistance to burning. “We cracked the code and rewrote it,” Susan said. “Now, you can build up to 18 stories.”
With this seismic advance, and the increasing availability of domestically manufactured mass timber, new wooden buildings are poised to provide an additional service in the form of climate mitigation. Compared to concrete, a wood superstructure uses about 40 percent less carbon, not including the carbon it stores. Additionally, the lifespan of these new structures is anticipated to rival the beloved old timber buildings drawing crowds from around the world to places like Seattle’s waterfront; that, in turn, boosts their economic valuation.
Atelierjones’ latest project, Heartwood, is an 8-story gem just minutes from the water, and one of the first affordable housing projects in the country built with CLT. Its 126 living spaces also house over one thousand metric tons of durable carbon. “It’s an important validation of the work we’re doing. I can’t wait to go replicate more.”
This profile is part of a series produced by the nonprofit Washington Farm Forestry Association (WFFA), which supports the stewardship of small family forest owners. The 218,000 small forest landowners in Washington account for about 15 percent of the state’s forests—nearly 3 million acres. Each year, these woodlands absorb an amount of CO2 equal to the tailpipe emissions from 875,000 passenger cars while also producing roughly 15 percent of the harvested wood products in the state.
In partnership with the Washington Tree Farm Program and the American Forest Foundation, WFFA is developing policy recommendations for the Washington legislature to encourage the voluntary participation of small family forest owners in markets that pay for storing carbon; and, in management techniques that improve carbon storage.
For more information, please contact Elaine Oneil, executive director of WFFA: eoneil@wafarmforestry.com.
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