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Case Studies  > San Francisco Federal Building Is a Breath of Fresh Air
Innovation meets tradition to create a ground-breaking structure
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Rendering Courtesy: Morphosis
At the new federal office building in San Francisco, concrete is playing a key role in merging innovation with tradition. Set for completion in 2005, the 18 story concrete office tower will take 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 will feature 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. John Nolte, project manager/construction engineer for owner General Services Administration (GSA), explains: “The underside of the form is fluted. The upper side of the deck has cavities that comprise the under-floor distribution system.” The under-floor distribution system offers tenants flexibility and energy savings, he says, and the fluted surfaces enhance natural air flow.

Sustainable design and construction shouldn’t rely only on modern technologies,
says Tim Christ, project manager for architectural firm Morphosis. “People have
gotten away from some of these timeless ideas,” he says. “We’re trying to return to them.” Concrete’s thermal mass has been used to reduce HVAC needs for generations.

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. Nolte says the building will use 50% less energy than a comparable conventionally built structure.

The project team will apply for Leadership in Energy and Environmental Design (LEED) Gold certification, says Nolte, noting that the project is a first in many ways. “GSA has always tried to employ energy savings,” he says, “[but] this design is unique. I’ve never worked on anything like it.”