AKA: Unico Properties, LLC, International Business Machines (IBM) Corporation, Office Building and Garage, Downtown, Seattle, WA

Structure Type: built works - commercial buildings - office buildings

Designers: Bouillon, Griffith, Christofferson and Schairer, Mechanical Engineers (firm); Naramore, Bain, Brady, and Johanson, (NBBJ) (firm); Unico Properties, LLC (firm); Worthington, Skilling, Helle and Jackson, Structural Engineers (firm); Wright, Howard S., (HSW) Construction Company (firm); Yamasaki, Minoru, and Associates (firm); William James Bain Jr. (architect); William James Bain Sr. (architect); Clifton J. Brady (architect); James Fitzgerald (sculptor); Helge Joel Helle (structural engineer); Joseph F. Jackson (structural engineer); Perry Bertil Johanson (architect); Floyd Archibald Naramore (architect); John Bower Skilling (structural engineer); Norman George Warsinske (interior designer/sculptor); Harold L. Worthington (structural engineer); Howard S. Wright (building contractor/developer); Minoru Yamasaki (architect)

Dates: constructed 1962-1964

22 stories, total floor area: 336,330 sq. ft.

1200 5th Avenue
Downtown, Seattle, WA 98101-3132

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In 1915, the Metropolitan Building Company erected the controversial Arena Building on this block, bounded by 5th Avenue on the west, University Street on the north, 6th Avenue on the east and Seneca Street on the south. This two-story multipurpose building was altered in 1925 into a parking garage, designed to serve the new Olympic Hotel (1924). This garage stood on the site until the early 1960s. Architect Minoru Yamasaki, a University of Washington graduate, provided the design for this IBM Office Building for Unico Properties, LLC, the real estate arm of the University of Washington; NBBJ served as Associate Architects, working on the design and doing site supervision. The Plaza Fountain by James FitzGerald, sculptor. Worthington, Skilling, Helle and Jackson served as Structural Engineers; Bouillon, Griffith, Christofferson and Schairer as Mechanical and Electrical Engineers; Jaros, Baum and Bolles as Consulting Engineers; Howard S. Wright Construction Company was the General Contractor. According to an article in the Architectural Record, 12/1963, p. 107, the building was scheduled for completion in 07/1964.

The structural design for the IBM Building in Seattle, WA, served as a prototype for that of the World Trade Center, New York, NY. Yamasaki wrote of the building's structural plan: "To provide flexible, open office space, the 115-foot-square building is clear-span form core to exterior stud wall. Floor and core systems are of concrete, while the wall structure is composed of four-and-a-half-inch diameter stel-pipe columns on twenty-eight-inch centers, with fireproofing of plaster inside and an exterior finish of precast aggregate-concrete units." (See Minoru Yamasaki, A Life in Architecture, [NY: Weatherhill, 1979], p. 104.) The IBM Building contained 336,330 gross square feet, 224,945, net, in 2010.