Salesforce Tower

by Darren Medeiros, Utelite Corporation

Owners: Boston Properties and Hines Interest LP

Architect: Cesar Pelli and Associates

Developer: Boston Properties

Engineer: Magnusson Klemencic Assoc.

General Contractors: Clark Construction Group and Hathaway Dinwiddle

Concrete Supplier: CEMEX USA (Redwood City, CA)

Lightweight Supplier: Utelite Corporation (Coalville, UT)

Project Location: 101 1st Street (San Francisco, CA)

Size: 1.4 million sq. ft., 61-story skyscraper (tallest building in SF, 2nd tallest west of the Mississippi River – 340m)

Completion Date: 2018

Project Cost: $1.1 Billion

Boston Properties and Hines have selected Clark along with joint venture partner Hathaway Dinwiddie Construction Company (Clark/Hathaway) to commence construction activities for the Salesforce Tower at 101 1st Street. The 61-story Class-A office tower would be the tallest building in the western United States at 1,070 feet, rising above the adjacent transit center in downtown San Francisco. When complete, Salesforce Tower would surpass New York City’s Chrysler Building as the seventh tallest building in the country.

Clark/Hathaway anticipates commencing construction activities at the site in mid-August with below-grade work. Salesforce Tower will be founded on rock by way of cast-in-place foundations extending down approximately 265 feet. The initial phase of below-grade work includes excavation, shoring and foundations necessary to support a three-level below-grade parking structure. At the ground level, Mission Square plaza will connect to the transit center’s rooftop park and provide a well-designed public open space for workers and the public alike.

A uniform steel and glass curtain wall system will wrap the tower’s structural steel framing, which itself will surround a concrete core. A dramatic crown of glass, metal mullions and partially open metal screen will sit atop the tower. The Salesforce Tower project is designed, at a minimum, to achieve LEED Gold certification and will feature an underfloor 100 percent outdoor air distribution system, high-performance glazing and integrated sun shades to reduce energy consumption.

Pelli Clarke Pelli Architects and Kendall/Heaton Associates are the leading the design team. Additional project partners include Magnusson Klemencic Associates, Seattle, structural engineer; WSP Flak + Kurtz, New York, MEP engineer; BKF, Oakland, civil engineer; ARUP, San Francisco, geotechnical consultant; and PWP Landscape Architecture, Berkley, Calif., landscape architect.

Project Requirements

  • Structural lightweight concrete meeting Magnusson Klemencic Associates performance criteria/ ASTM C-330 specification requirements
  • 12,000 cu. yds. of “3/8″ Mediums” expanded shale lightweight aggregates
  • Minimum Flexural Strength: 650 psi @ 56 days
  • Yield Strength: 5,000 psi @ 28 days