When the City of Tacoma was about to demolish one of its deteriorating “unsavable” downtown parking garages, PCS Structural Solutions Chairman Dan Putnam, who had studied the building, decided to do better. As developer, Putnam would rehabilitate the garage, add one level of parking and two of speculative offices, and upgrade the ground floor for large-scale retail – all economically with a Class A end product. PCS would not only be structural engineer but also relocate its Tacoma offices to the building.
The original structure had been built to handle two more levels, but not three, and not the hoped-for green roof. To keep costs in check, the addition needed a light structure to avoid foundation upgrades. PCS implemented an innovative cellular beam system, which is 25% lighter than standard steel beams. The system allowed 60 foot spans (a record for office occupancy), matching the spans in the garage to avoid transfer elements and improve office layouts. This allowed enough reserve capacity in the foundations to accommodate a green roof, a major part of achieving LEED Platinum.
For its own 14,000 square foot space, PCS kept the cellular beams exposed, as a testament to the firm’s ingenuity. The other 86,000 square feet have done well, with 100% occupancy.
