The Key at 12th (1100 Broadway)

Oakland, CA

The Key at 12th (1100 Broadway)

Integrating the eight-story Key System Building—a landmark structure constructed in 1911—with a new 10-story tower, this office development was designed to meet foundation requirements associated with its unique location above a BART tunnel station downtown. The new tower’s upper floors cantilever approximately 25 ft over the Key System Building, maximizing floorplates and allowing the new building to combine and contrast with the historic structure.  This design was achieved by incorporating lightweight concrete slabs on composite-steel decking and placing two-story steel trusses on three exterior sides.  These 100-ft-long trusses located at the end of the cantilevered bay eliminated the need for interior trusses and transferred loads to 25-ft-long cantilevered trusses on the structure’s east and west perimeters.