SF Public Utilities Commission HQ
Location: San Francisco
Owner: City & County of San Francisco; SF Public Utilities Commission
General Contractor: Webcor Builders
Architect: KMD Architects
Seismic Consultant: Tipping Mar
Grand opening: June 21, 2012
Recent Award: 2103 AIA COTE Award Winner: Top Ten Green Projects in the United States
Status: As of June 2012: Greenest Office Building in San Francisco
Low-CO2 Concrete from Central Concrete
Central Concrete supplied its high-performing, low-CO2 concrete for the new SF Public Utilities Commission Headquarters (SFPUC), San Francisco’s newest and greenest office building. The 13-story, 277,5000-square-foot LEED Platinum building’s innovative use of concrete significantly reduced the project’s carbon footprint and saved 7.14 million pounds in CO2 emissions.
Original plans for SFPUC HQ called for a 12-story building with a steel frame, but ultimately the SFPUC decided to adopt a resilient post-tension concrete structure design. Developed by Tipping Mar, a leading structural engineering firm in Berkeley, California, this innovative design returns a building to plumb after a seismic event.
During the redesign phase, team members — KMD Architects, SOHA Engineers, Tipping Mar and Webcor Builders – invited Central Concrete to a charrette to find the greenest concrete mix possible. At that point, Central Concrete had not yet been selected for the project and was not paid for the charrette. The team looked to Central to suggest solutions for their aggressive goals – a set of concrete mixes that delivered up to 70% cement replacement materials, with no compromises on cost, finish or cure time for the mat foundation, slabs, columns and cores.
Meeting the aggressive goals, Central Concrete, in an open public bidding process, was selected for the job. Central’s solution offered numerous advantages. Not only did Central Concrete beat Tipping Mar’s own record of specifying 56 days of cure time, but the SFPUC was able to add a 13th floor due to the concrete’s reduced floor-to-floor height, and the concrete structure eliminated the sunlight-blocking beams. Central’s six different mixes significantly cut the Portland cement content and delivered a net savings of 7.14 million pounds in CO2 emissions from embodied carbon — nearly 50% better than traditional concrete mixes.