S.F. hopes to set example with new green tower

[Swamp Gas]

www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2007/04/13/MNGVFP852Q1.DTL

S.F. hopes to set example with new green tower

John King, Chronicle Urban Design Writer

Friday, April 13, 2007


San Francisco's Civic Center is the proposed home of a government tower that city officials say will be more energy-efficient than any large office building in the United States.
The headquarters of the city's Public Utilities Commission would include design features rarely seen in comparable buildings, such as wind turbines on the roof and a water recycling system in the basement. Solar panels would be embedded in outer walls, and a ventilation system using "thermal chimneys" on each floor would pull hot air out of the building.
The PUC wants to break ground next spring on the 12-story structure at 525 Golden Gate Ave., half a block from City Hall. And while the sustainability measures add $16 million to the $178 million price tag, agency officials say it's important that PUC headquarters use as little energy and water as possible.
"We can't ask people to change their way of doing business and not put our money where our mouth is," said Susan Leal, the agency's general manager.
Agency consultants go so far as to describe the project as "the most energy-efficient office building developed in an urban setting in the United States to date."
While that claim is difficult to verify, sustainability experts agree the PUC's approach is an unusually aggressive example of "green" design -- even at a time when the global warming debate has focused attention on environmental issues.
"It sounds as though everything they're planning is a degree beyond what we're seeing elsewhere," said Andrea Traber, president of the Northern California chapter of the United States Green Building Council. In a tower being marketed to private office tenants, she said, "developers would consider a lot of this to be expensive fluff."
The "fluff" includes corkscrew-like wind turbines that would be situated on the roof and stacked vertically behind glass walls along Golden Gate Avenue.
Similarly, gridlike photovoltaic panels that "harvest" sunlight would be woven into the south-facing facade and into a 15,000-square-foot cap above the rooftop's mechanical systems.
Together, these elements will cost an estimated $3.1 million while generating 40 percent of the building's energy.
The initial goal was more ambitious.
"I wanted us to design a building completely unconnected to the electrical grid," said Anthony Irons, the PUC's deputy general manager.
That wasn't possible because room for solar panels is limited -- the roof is only so big, and nearby buildings cast shadows.
Still, the turbines and panels together should generate more than 100 percent of the tower's needs on days when there's a stiff wind and low temperatures.
The site, next to Trader Vic's restaurant, contains a state office building that closed because of damage from the 1989 Loma Prieta earthquake. The city purchased it for $1 and drew up plans to develop a City Hall annex, but work was stopped in 2002 because of budget concerns.
The PUC revived the project last year, seeing 525 Golden Gate as an ideal place to consolidate its 1,000 employees now working in rental space that costs the agency $9 million annually. In contrast, the estimated cost to house all employees in the new building is $3.8 million per year.
The basic design by Kaplan McLaughlin Diaz Architects and the engineering firm Arup remains the same: squat and restrained, glassy on the north but with generous amounts of Sierra white granite on the south and east sides in deference to City Hall and other Civic Center buildings.
The green tinge isn't new either -- the project was intended from the start to be a municipal showcase of sustainability.
But the delays have a bright side. The quest for energy-efficient buildings has fueled the creation of products and materials that five years ago were cost-prohibitive or nonexistent.
The initial design did not include wind turbines, for instance. The ones then on the market vibrated too much and came with windmill-like blades that kill passing birds.
Since then, Chicago manufacturer Aerotecture has devised a turbine -- one is installed outside the Randall Museum in San Francisco -- that is lightweight and generates power in slow-moving, elegant swirls.
"Technology caught up with what we wanted to do all along," said Ned Kahn, a Bay Area artist who has been involved in the project from the start. "There's no vibration, they're inherently safe for birds -- but they're also beautiful."
The PUC project is just one example of how government has embraced green design, once a fringe movement.
Bay Area municipalities and counties -- including San Jose, Oakland, and Alameda and San Mateo counties -- now require that new public structures be built to standards established by the U.S. Green Building Council. At the federal level, the new General Services Administration tower near Civic Center includes operable windows and recycled concrete, though it lacks solar power and wind turbines.
The PUC's Irons was the city architect before joining the PUC. He oversaw the $316 million restoration of City Hall, from the marble in the lobby to the gold leaf on the dome.
"City Hall is the people's building ... it makes a statement of grandeur and importance and welcome," Irons said when asked to compare the two projects. "This building makes a different sort of statement. The world's a different place now, with different dangers and challenges. It's addressing a global issue."
The project will be funded by a combination of bonds sold against future rent savings, and the sale of surplus PUC property. Monthly water and wastewater rates will not be affected.
The building itself does not need approvals, since it fits within approved zoning. However, the PUC and the Board of Supervisors still must authorize the use of the bonds.
Commission members gave initial support to the approach on March 27. Irons said the agency hopes to take the project to the supervisors within the next month.
Green features
It might look conventional, but a new PUC headquarters near City Hall would include several green design innovations:
-- Wind turbines stacked behind glass along part of the facade and on the roof to generate energy.
-- Solar panels on the 12-story tower's roof and embedded in portions of the facade.
-- Waterless urinals, faucet sensors and on-demand water heaters to restrict use to 5 gallons per occupant per day.
-- Wastewater recycled through basement filters, then put to use in toilets and the cooling system.