2010 EEA National Gold Award Winner – Cary Kopczynski & Company’s Escala

Gold Award – Structural Systems

Cary Kopczynski & Company – Escala

Client: Mulvanny G2 Architecture

The goal with Escala, a 30-story luxury condominium tower in downtown Seattle, was to create large, open spaces, unimpeded by walls and columns. Cary Kopezynski & Company (CKC) worked closely with the owner, architect and contractor during conceptual design to create a structure that complemented the design, minimized construction costs, shortened the construction schedule and met the overall goals for this project.

CKC developed a dual system for seismic resistance that incorporates minimal shear walls at the stairs supplemented with ductile moment resisting space frames (DMRF). This non-conventional dual system worked perfectly with the architectural layout, without compromising the open and spacious unit plans that were key to the Escala vision. This seismic system required an exceptionally high concrete strength of 14,000 psi at the lower levels of the building. Working with the City of Seattle, CKC got approval to use reinforcing bar with a yield strength of 100 ksi, in lieu of traditional 60 ksi bar. Additionally, to allow private entries into each residence, double-door elevators were located at the building extremities. Escala became the first building in North America, and perhaps the world, to use 100 ksi steel for seismic reinforcing. The 40 percent reduction in steel requirements reduced rebar tonnage, congestion and field labor, allowed use of traditional vibrators for concrete placement, and helped accelerate the construction schedule. As high strength rebar becomes more widely available and its benefits more clearly understood, the value to the engineering profession will be enormous.