Wolff Company and Katerra Partner to Design and Build a Two-Building 5-Story Project Using CLT

Developer The Wolff Co. has partnered with the technology-driven construction firm Katerra to design and build a two-building, five-story project, which is among the first developments in the country to use cross-laminated timber (CLT), or large-scale, prefabricated, solid engineered wood panels, for the floor and ceiling assemblies. Built on the former site of Shoreline, Washington’s post office, The Postmark is a new 243-unit, mid-rise apartment community 10 miles north of downtown Seattle. It is Katerra’s first residential CLT project, utilizing European CLT prior to its Spokane Valley, Washington–based factory being operational in 2019. Katerra used virtual design and construction as well as 3D modeling to create a building prototype and manufactured the components completely off-site. The prefabricated panels arrived on-site with all joints precut, to extremely low tolerances, enabling the crew to install an entire 30,000-square-foot floor in three days. Beyond the aesthetic value of the exposed wood ceilings and beams in the units and communal areas, the European CLT, along with glulam beams, used for the floor slabs and roof structures reduces structural loads and increases build efficiency when compared with concrete and steel, according to the firm.