The Maritime Building, constructed in 1910, was originally a 5-story building rectangular-shaped in-plan with a single basement parking level. The exterior of the buildings consists of reinforced concrete frames and the interior structure is of heavy timber post and beam construction. The wood posts are on a 15’ x 20’ grid and are continuous down to the foundations. The foundations are timber piles with concrete pile caps.

The addition consists of two stories of offices and a roof penthouse constructed with steel framing. The addition is constructed over the existing 5-story timber building. New perimeter steel cruciform columns located inside the existing concrete perimeter walls and strengthened interior concrete columns support the added floors.

New steel buckling restrained brace frames on 3 sides of the central office core and on each side of the exterior walls provide the seismic resistance for the existing building and the proposed addition. At the typical existing floors, plywood sheathing, collectors, and drag elements have been provided to deliver seismic inertial forces to the new lateral resisting system.