Waugh Thistleton and Mithun design US's tallest mass-timber office building in Bellevue

Waugh Thistleton Architects, in collaboration with Mithun, has introduced plans for Bevel, a 12-storey mass-timber office structure set to rise in Bellevue, Washington. Once finished, it will hold the title of the tallest timber office building in the United States. Developed by Skanska, the 55-metre edifice will incorporate a hybrid design of timber and steel, showcasing exposed mass-timber columns, beams, and ceilings. This initiative marks Waugh Thistleton's inaugural project in the US, with co-founder Andrew Waugh emphasizing timber's potential in American architecture. WoodWorks CEO Jennifer Cover pointed out that Bevel broadens the scope for tall timber developments, with only three out of 22 such buildings being commercial. The building will rest on a concrete foundation with a car park, while a timber structure above is supported by a steel core and seismic features. Mithun partner Craig Curtis noted that mass timber facilitates more open floor layouts and a side core, enhancing leasing opportunities and achieving cost equivalence with concrete. The project team includes civil engineer Coughlin Porter Lundeen, landscape architect Hewitt, and structural engineer Holmes, among others.