When architecture engages social, cultural, political, and ethical currents, it has the potential to transform the way we see the world and our place in it. It is from this intersection of broad societal currents that we approached the design for the new Federal Building in San Francisco. Our primary interest was to produce a performance-driven building that would fundamentally transform its urban surroundings, the nature of the workplace, and the experiences of the people who use it while making intelligent use of natural resources. For me, this project represents the epitome of an optimistic architecture; an architecture that synthesizes its complex forces and realities into a coherent whole. Thom Mayne
Building Description: The slender, 18-story, 240-foot tower creates a landmark for the City of San Francisco, while the four-story annex connects to the scale of the adjacent neighborhood. The large, open public plaza along with the shared public facilities, provide valuable assets to the community. In addition, the design redefines the culture of the workplace through office environments that boost workers’ health, productivity and creativity. A dramatic example of sustainable design principles, the building’s shape and orientation maximize natural airflow for cooling and ventilation, and take advantage of natural day light for the majority of the office interior. These features, combined with a number of other energy-saving elements, significantly reduce overall energy consumption compared to conventional commercial office buildings in the United States.
Building Materials: The San Francisco Federal Building incorporates building materials and construction strategies that minimize waste and energy consumption. The building minimizes pollution by replacing high proportions of Portland cement in its concrete foundations and frame. During the manufacturing process, Portland cement is associated with very high levels of greenhouse gas emissions. In the Federal Building’s concrete mixture, 50% of the pollution-intensive Portland cement is replaced with blast furnace slag, a recycled waste product from the steel industry, significantly reducing greenhouse gas emissions resulting from conventional concrete. This environmentally sound choice also results in higher-strength concrete and has a warm, light-colored tone that contributes to the favorable daylight penetration within the office space. The GSA mandated that 75 percent of materials used during construction be recycled. Currently, the project is recycling 87 percent of its waste material. Carpet, paint and furniture were carefully considered with respect to the project’s sustainable goals.
Electrical: Lighting is typically the largest energy cost for an office building, representing up to 40 percent of a facility’s total energy load. The new San Francisco Federal Building’s lighting strategies improve the workplace and are a critical facet of this project’s sustainable design. Approximately 85 percent of the workspace is illuminated with natural light. Ambient light, the general illumination in an office, comes from sunlight channeled through the windows and reflected off walls and ceilings to extend its reach with minimum glare and intensity. With an average overall ceiling height in the tower of 13 feet, natural daylight will penetrate deep into work spaces. Powered lights are also provided to supplement the natural light. Through simple sensors, the building’s automated systems manage the balance between powered and natural daylight. The powered lights are on only when people are at their workstations. Together, these approaches reduce energy used for lighting by approximately 26 percent.
Work Environment: Several features support federal initiatives to promote health and improve productivity: the location of the cafeteria on street level across the plaza and the use of skip-stop elevators—elevators that stop at every third floor, opening onto soaring lobbies with wide, open stairs—promote cardiovascular fitness and reduce lost work hours. These lobbies and stairs, in addition to a sky garden and a 90-foot high entry lobby at street level, provide a comfortable setting for informal meetings and social interaction. A handicap accessible elevator that travels to every floor is also available. The tower’s high ceilings and glass facades provide 85 percent of the building’s tenants with views overlooking the city. The outer perimeter of the tower is configured with open offices and 52- inch-high workstation partitions, maximizing access to natural light. Fritted glass panels that enclose meeting rooms and offices located in the middle “spine” of the tower, provide both privacy and access to natural light.
Quality Control: Three independent systems are used to verify that the building is meeting energy conservation goals. Energy use will be monitored by the GSA Energy Center and compared with conventional federal buildings and the project’s goals. To verify sustainability, the project is registered with the LEED program. The project team and the GSA’s Office of Applied Science have allied with a number of academic researchers to verify workplace productivity strategies. Among them: Lawrence Berkeley National Laboratory, Carnegie Mellon University’s Center for Building Performance and Diagnostics, and the University of California Berkeley, Center for the Built Environment.