The renovation of the century-old Maritime Building on the Seattle waterfront preserved the structure’s historic exterior while opening up the interior for modern use. The project renovated 186,000 sq ft of the building while adding another three stories. The primary challenge was preserving the building’s structural integrity during construction.

Modernizing the building required demolishing the concrete exterior elevator shafts and firewalls while also removing the building’s core. Meanwhile, crews were installing new micropiles and pile caps in the basement to support the new steel structural core and the additional stories. Since the site’s water table was 3 ft below the existing slab, integrating new micropiles to support pile caps was critical. To showcase the original old-growth timbers in the building’s core, the team reused them in the new outside decks.