By: Jacob Dunn, LEED AP® BD+C

The Portland International Airport (PDX) will be the first major airport in the US with a mass timber roof, where at least the secondary beam structure and roof deck are mass timber elements. The use of mass timber at the airport is a natural choice. It made PDX not only a highly sustainable and beautiful civic building, the accomplishment also reflects our industry’s values around environmental stewardship, climate action, and regional equity.

Wood is a beautiful, durable, and a renewable building resource that provides biophilic benefits with its inherent warmth that helps ease the passenger experience. Timber is “in our blood” as we say in the Pacific Northwest, a region with a long cultural and economic history intertwined with the forest. Luckily when sourced correctly, wood can be ecologically restorative while living up to its promise as a climate solution when compared to more carbon-intensive building materials like concrete and steel. However, consumers don’t typically know very much about how their wood was sourced. The current opaque wood supply chain makes it difficult to know how the wood was harvested, exactly where it was harvested, who owned the land, and the values that drive its forest’s management. For any given building project, it’s a mystery how much wood came from small, family forests practicing regenerative forestry, or how much came from investment corporations managing forests for their shareholders who aren’t in the region. Yet, if the salmon that we consume can be tracked back to its source of origin, and our coffee traced back to the farm where it was grown, why can’t we know where our wood comes from? And even better, why can't we know how that wood was harvested?

At the outset of the PDX Airport’s new main terminal project, ZGF and our client, the Port of Portland, posed a question: Can we source all this wood in a way that is better for the land and better for our local communities? This challenge became an opportunity to innovate our wood sourcing strategy. Together with our project partners—a collaboration led by the Port of Portland, with ZGF, Sustainable Northwest and Sustainable Northwest Wood, Hoffman Skanska Joint Venture, Swinerton, and Timberlab—we were able to track a good portion our wood back to its forest of origin and actually influence where it came from. This procurement approach ensured better outcomes for both the forests and the rural communities that manage them. The design team and client team visited five of the forests and learned firsthand from the landowners how and why they stewarded their land. The result is local architecture that goes far beyond the notion that “trees grow in the PNW, so we’ll put wood products in our building.” Rather, using wood in a project is an opportunity to go deeper and reconnect the building to the land and community that created it, effectively rooting the project in place.

Referred to as “Forest to Frame”, a play on the farm-to-table movement, PDX’s sourcing approach revolved around meeting the following goals:

Traceable

Over 1,000,000 of the 2,600,000 board feet in the wood beams and ceiling lattice can be traced back to its forest of origin through direct sourcing approaches.

This traceability allowed the project to tell the local story of the wood, its ecological impact, and community benefits in new ways. For instance, we can track 100% of the 600,000 board feet of ceiling lattice back to best-in-class forest restoration sources from 11 different Oregon and Washington landowners, including small family forests (Hyla Woods, Hanschu Family Forest, Camp Namanu, Camp Bishop, Camp Adams), local tribes (Coquille Indian Tribe, Skokomish Indian Tribe), non-profits (The Nature Conservancy), community forests (Chimacum Community Forest and Roslyn City Forest), University experimental forests (Willamette University), and publicly owned land (Joint Base Lewis McChord). For the 2,000,000 board feet of glulam beams, we directly sourced 400,000 board feet of it from both the Yakama Nation (370,000 board feet) and the Coquille Tribe (30,000 board feet), the former being the largest single landowner who contributed to the project.

The project imperitive of transparent wood procurement enabled the Port of Portland to know everything about the forestry practices of their wood, from how the trees were harvested, down to the size of the harvest opening and how many trees were left behind for retention. For instance, the largest harvest opening for the PDX Airport lattice was a 12 acre harvest with 15% wildlife tree retention. This is a tremendous improvement compared to what could have been with the legal requirement of a maximum 120 acre harvest with less than 1% of trees left behind. The increased retention we were able to achieve is key for continuity in ecological function after a disturbance such as a commercial harvest.

Critically, greater transparency in the wood supply chain also allows us to connect with the land owners and communities who supply it, uplifting their stories and celebrating their contributions to the largest construction project in the history of Oregon.

Equitable

It was essential to the team and client to target and celebrate the underrepresented parts of the supply chain.

This meant going the extra mile to make sure the project sourced its wood from small mills, small family forests, non-profits, and tribal nations. Over four tribes are represented in the overall project (Yakama Nation, Coquille Tribe, Skokomish Indian Tribe, Cow Creek Umpqua Tribe of Indians), and multiple small landowners from both Oregon and Washington are featured because of our transparency-based sourcing approach.

While we were able to learn so much about alternative procurement strategies with PDX, our goal now is to make sure it doesn’t become a monument to the unattainable. Currently, we are working with multiple new clients on evolving PDX’s sourcing frameworks in ways that are scalable for all project types and sizes. Additionally, ZGF recently joined the Colorado Mass Timber Coalition, is active in the Climate Smart Wood Group, and is working with architects across the US to co-create transparency specifications and other publicly available resources to replicate this approach in other regions. We’re already seeing other projects replicate portions of the PDX framework with efforts right sized to their goals and aspirations.

These efforts are timely, as we are seeing more and more of our clients become deeply interested in the impact of their supply chains. From tech companies interested in ESG reporting to healthcare clients seeking more connection with the communities they serve; these new procurement approaches give us, and most importantly, our clients—the opportunity to bring our values to life through our work.