San Francisco Federal Building Is a Breath of Fresh Air.
Innovation Meets Tradition to Create a Ground-Breaking Structure
At the federal office building in San Francisco, concrete plays a key role in merging innovation with tradition. Completed in 2007, the 18-story concrete office tower takes advantage of the city’s coastal breezes, incorporating a modern glass façade with movable elements that open and close—a timeless approach to ventilation.
The 600,000-square-foot building has a narrow dimension of 60 feet, capitalizing on concrete’s strength with shear walls (around the elevator core and two plumbing shafts) to meet the challenges of the local seismic environment and the unique footprint. The use of concrete for such an application is atypical in an area that usually embraces steel, but large amounts of concrete are essential to facilitate a natural ventilation and cooling approach that takes advantage of thermal mass.
The interior of the building features exposed concrete ceilings, columns, and walls. Remote-controlled façade elements that open in the evening will release warm air, bringing in cooler air to reduce the building temperature. The cooled-off concrete will help regulate temperatures throughout the day.
One of the structure’s most innovative components is the cast-in-place floor system, constructed with specially designed forms.
“The underside of the form is fluted. The upper side of the deck has cavities that comprise the underfloor distribution system,” said John Nolte, project manager/construction engineer for owner General Services Administration (GSA).
The underfloor distribution system offers tenants flexibility and energy savings, and the fluted surfaces enhance natural air flow, he said.
Sustainable design and construction should not rely only on modern technologies, said Tim Christ, project manager for architectural firm Morphosis.
“People have gotten away from some of these timeless ideas,” he said. “We’re trying to return to them.”
Concrete’s thermal mass has been used to reduce heating, ventilation and air-conditioning (HVAC) needs for generations, he said.
A unique concrete mix is also lowering lighting costs: slag cement (which is almost white) mixed along with portland cement lightens the concrete significantly, increasing reflectivity throughout the structure.
The building will use 50 percent less energy than a comparable conventionally built structure, Nolte said.
“GSA has always tried to employ energy savings,” he said, “[but] this design is unique. I’ve never worked on anything like it, he said.
The San Francisco Federal Building won a Design Award from the AIA San Francisco chapter in 2008. The award praised the buildings open spaces and environmentally friendly design.
The building earned LEED® Silver certification from USGBC.
In June 2012, the San Francisco Federal Building was named The International Outstanding Building of the Year (TOBY) in the government category. GSA was recognized by the commercial real estate industry for quality in commercial buildings and excellence in building management and operations.
Rendering courtesy of Morphosis
General Services Administration (GSA). San Francisco, California
Morphosis, New York, New York
Smith Group, San Francisco, California
Structural, MEP Engineers:
Ove Arup, San Francisco, California
Dick Corporation, Large, Pennsylvania, and
Morganti, Danbury, Connecticut