First Mass Timber Middle-Income Housing Development in U.S., Tallest Mass Timber Building in Washington Hits Topping Out Milestone

Swinerton has topped out the nation’s first middle-income housing development constructed of mass timber; and the tallest mass timber building in Seattle, Washington. Heartwood is a workforce housing development standing at eight stories and 67,000 gross square feet. With a target completion in spring 2023, Heartwood will provide 126 affordable rental units, filling a critical need for middle-income workers such as teachers, nonprofit employees, healthcare professionals and others who are increasingly priced out of high-cost cities.

The company joined the project team in a design-build capacity for the overall construction, including the mass timber structure which was detailed, fabricated and integrated by Timberlab. Through the design phase, Swinerton worked with architect, atelierjones and structural engineer, DCI Engineers. Swinerton also led meetings with the Seattle Department of Construction and Inspections to propose solutions that address fire and life safety during both construction and occupancy.

In addition to the 126 studio and one-bedroom apartments, the project also will feature a lobby, retail space, shared courtyard, firepit, BBQ area and multiple bike storage rooms. Constructed in just over 12 months, the building features exposed, eco-friendly cross laminated timber ceilings and glulam beams within the units, hallways and lobby, which lower the overall carbon footprint of the structure by almost half, compared with more traditional construction methods.