Rainier Square Tower

Seattle, WA
Rainier Square

The Erection Company was the steel erecting contractor on the Rainier Square Tower, an 850-foot-tall, 58-story project that utilized a brand new engineering design termed “speed core.” Speed core uses a coupled steel-plate composite shear wall in which the cross-tied plates are filled with concrete, increasing seismic resistance and avoiding rebar congestion.


Rainier Square occupies the prominent position in Seattle’s skyline. The 1.1M square foot project includes a 58-story tower containing 722,000 square feet of office space and 189 luxury apartment residences on its uppermost floors with 360-degree unobstructed views. The base of the tower includes a unique mix of destination retailers, such as PCC Community Market and Equinox Fitness, making this a block unlike any other in Seattle. The entire block is connected through Floor 2, providing direct convenient access to Rainier Square, Rainier Tower, 400 University, the Grand Hall and light-filled Library with its fireplaces, inner courtyard and adjoining coffee, wine, pastries, and juice bar.


The Erection Company was able to deliver the project in just 10 months, which is estimated to be twice as fast as a perimeter steel frame joined to a reinforced concrete core. In order to accomplish this design and deliver on the speed promises, we needed to complete a great deal of field welding on Rainier Square.