Part of this project was PSG's renegotiation of existing WaMu leases for 750,000 square feet in neighboring buildings. This provided for a gradual exit throughout 2006 to accommodate WaMu Center phased occupancy.

PSG and the Seneca Group managed the project from concept through design involving multiple architectural firms, permitting, construction and the occupancy by Washington Mutual of more than 4,000 employees. The offices and garage opened in March 2006. The SAM expansion opened in May 2007.

This project required several changes to the City's Land Use Code to allow the City to accomplish its goal of accommodating this unique corporate and public institution partnership, particularly related to floor-area-ratio calculations and the related requirements of museum space.