"Our intent from the beginning was to create the most energy-efficient office building developed in an urban setting in the United States to date," said PUC deputy general manager Anthony Irons. The $178 million, 254,000-square foot headquarters will include features uncommon in buildings today, but "would be commonplace in years to come," he said.
Officials say construction will be paid by selling surplus real estate holdings and by issuing bonds against future rent savings, not by funds from rate-paying customers.
Dozens of wind turbines on the roof, solar panels embedded in outer walls, and a natural-cooling "thermal chimney" are among the features enabling the structure to supply 40 percent of its own energy needs, said Hobstetter. On windy, sunlit days, it will go off the power grid completely.
"The San Francisco PUC headquarters is the type of well-proportioned, elegant project that reveals the next wave of thinking by designers and planners in which the building is seen as a component of its natural setting. The possibilities for innovation are limitless; just think of a city that regenerates rather than depletes its natural resources," said Lisa Sullivan, Director of Publications, "Places: Forum of Design for the Public Realm", a journal sponsored by a consortium of design schools including U.C.-Berkeley, the Pratt Institute and M.I.T.
Planned to break ground at 525 Golden Gate Ave. near City Hall in 2008, the PUC headquarters also employs advanced water-saving and water-recycling. Faucet sensors, waterless urinals, and on-demand water heaters will cut use to 5 gallons per occupant per day, compared to average office-building use of 25 gallons a day. A grey-water wastewater recycling system enables reuse of water from faucets and sinks in the building's toilets and the cooling system.
While water and power efficiencies were the PUCÂ’s primary goals, the new headquarters will also employ leading-edge design concepts in enhancing human performance, said Hobstetter.
"Dozens of research studies have confirmed the benefits of natural daylight and views of greenspace in improving a person's productivity, reducing absenteeism and improving health and well-being," said Hobstetter.
"By utilizing sun-filtering shades, new window-glazing materials and other techniques, we were able to bring sunlight well inside the structure's interior work spaces."
"Energy efficiency is one thing, it can be accomplished with smart technology; it is easily measured," said Ryan Stevens Design Principal at KMD. "We want to go one step further and provide a work space that will contribute to preserving the environment, foster interaction, creativity and productivity and also inspire the community."
The building is designed to exceed LEEDs-Platinum, and will exceed California's recently instituted Title 24 requirements for energy efficiency in new office buildings by 60 percent, he concluded.