THA Architecture, Portland, Ore.

THA Architecture, Portland, Ore.

Credit: Kyle Johnson


THA Architecture’s office in the historic Balfour Guthrie building in Portland, Ore., stands at the intersection of the city’s two, slightly skewed street grids. That explains the building’s wedge-shaped footprint. It’s also an apt metaphor for a firm that’s all about finding the balance between dualities: history and sustainability, continuity and change, upstairs and downstairs.

Balfour, Guthrie & Co. was a San Francisco–based shipping firm that sustained major losses in that city’s 1906 earthquake and fire. So when this building was constructed in 1913, THA principal Becca Cavell, FAIA, says, “one of the design drivers was that it be fireproof.” In 2001, when THA’s four senior partners bought the reinforced concrete building—then a rubber-stamp factory with ink-stained floors and painted-over windows—they took it in two directions at once, securing both LEED certification and a listing on the National Register of Historic Places.

THA Architecture, Portland, Ore.

A cut through the ground-level floor slab reveals square rebar embedded in the concrete.

Credit: Kyle Johnson


Behind the restored limestone façade, the firm’s two-story space exposes the building’s concrete bones, with a cutout in the ground-level slab that makes daylight available to the sub-grade level below. “It reflects the values we aspire to in our designs,” says Jonah Cohen, AIA, also a principal at the 40-person firm. “Natural light, expression of structure, human scale, enduring materials.”

Along with an open floor plan and workstations that are lined up “like a great big farm table,” Cavell says, the bi-level configuration supports the firm’s use of flexible project teams. “It reflects the way we operate,” Cavell says. “No one has a permanent desk,” and the imbalance between floors “really focuses us on moving people around.”

  • THA Architecture, Portland, Ore.

    Credit: Kyle Johnson

    The first-floor cutout allows light to penetrate the basement-level office area, where full staff meetings and occasional office parties are held.
  • THA Architecture, Portland, Ore.

    Credit: Kyle Johnson

    The historic building, originally designed by Morris Whitehouse, was the first architectural office to achieve LEED Silver certification.