GSA's new San Francisco Federal Building (SFFB) was designed by Thom Mayne, FAIA, principal of Santa Monica, California-based Morphosis, and the Los Angeles office of the international engineering firm Arup, which provided seismic, structural, mechanical, electrical, and plumbing services. GSA intended the 18-story, 605,000-square-foot SFFB to be a model of sustainable design. Many of the building's features will be precedent-setting for GSA. A narrow footprint ensures employees will have access to daylight. Skip-stop elevators are meant to encourage walking and social interaction. The building features extensive use of natural ventilation for cooling, thermal mass storage, and both passive and active shading strategies.

The building's exterior skin consists of a glazing system that incorporates computer-controlled operable window walls, which modulate the amount of natural ventilation across the office-tower floors according to space temperature, outside air temperature, wind speed, wind direction, and other environmental factors. The building also incorporates extensive use of daylighting to reduce dependency on electric lighting. For enclosed private offices and on lower floors, under-floor air-supply and overhead VAV air-distribution systems deliver conditioned air. There is a central chilled-water and hot-water plant in the facility.

The San Francisco Federal Building�s wavy, poured-in-place concrete ceiling increases thermal mass. The ceiling�s concrete beams are upturned and hidden by a raised-floor system for the floor above. Photo © Roland Halbe

Because the SFFB represents a milestone for GSA, the agency is conducting extensive post-occupancy evaluation (POE) to determine if the completed building is delivering the comfort, energy-efficiency and operating-cost savings it was designed to deliver. GSA plans to apply the results in a "feed-forward" process for future federal buildings.

GSA hired San Francisco-based Enovity to be the LEED commissioning authority for the HVAC, electrical, and building automation systems. Jonathan Soper, PE, a principal at Enovity, says they are still commissioning the Lutron lighting controls, which is typical for complex systems, but the majority of the firm's time is spent on the building management system (BMS), a direct digital system that runs HVAC-related equipment. At the SFFB, the BMS is referred to as the energy management and control system (EMCS). It's programmed with a sequence of operation, somewhat like a narrative, developed by the project's mechanical engineer to explain how the mechanical system should operate. "We're trying to refine that sequence so it can function in a way that makes sense for the building's occupants," Soper says.