Two Union Square

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Height: Architectural 225.6 m / 740 ft
Height: To Tip 242.8 m / 797 ft
Floors Above Ground 56
Floors Below Ground 4
# of Elevators 29
Tower GFA 112,970 m² / 1,215,999 ft²
# of Parking Spaces 1,128


Official Name Two Union Square
Structure Type Building
Status Completed
Country United States
City Seattle
Street Address & Map 601 Union Street
Postal Code 98101
Building Function office
Structural Material composite
  • Core: Reinforced Concrete
  • Columns: Steel
  • Floor Spanning: Steel
Energy Label LEED Certified O+M: Existing Buildings
Proposed 1984
Construction Start 1987
Completion 1989
Official Website Washington Holdings
Rankings Click arrows to view the next taller/shorter buildings
Regional Ranking #143 Tallest in North America
City Ranking #3 Tallest in Seattle

Companies Involved

Owner Unico Properties
Design NBBJ
Architect of Record NBBJ
Structural Engineer
Design Magnusson Klemencic Associates
MEP Engineer
Design Bouillon Christofferson & Schairer
Main Contractor Turner Construction Company
Other Consultant
• Façade Maintenance Manntech Building System
• Landscape Thomas L. Berger Associates

CTBUH Initiatives

CTBUH Study Examines Tallest Buildings with Dampers
22 Aug 2018 – CTBUH Research

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