March 2 (Bloomberg) -- Architect Thom Mayne has covered the 18-story south side of the San Francisco Federal Building with perforated metal panels. It's an armor that evokes Baghdad's Green Zone more than the California city's soft, fogged hills. Yet behind the bristling facade of this slim, $144-million slab lurks flower-power idealism. It's a building that addresses the growing concerns of global warming.

Mayne, principal of Santa Monica-based Morphosis, bracingly applies brute urban-industrial energy to his environmental agenda. The 3-foot-by-8-foot stainless-steel panels, which appear translucent, are supported in front of the all-glass building wall by a metal framework. Functionally, they shade the building from low winter sun, cutting daylight to a comfortable level for office workers.

That's just one of the ways the building cuts energy use. In total, it's designed to consume about half the power of a standard office tower -- an indication of how building design can help slash emissions of greenhouse gases.

Stylistically, Mayne has gone post-apocalyptic. The blanket of metal panels angles up over the roof and folds down at a slightly crazed angle to make a jaunty hat tipped to the city. Then it plunges down the south side, and undulates like a stock- market graph to shade a public plaza and the skylight-dotted roof of a child-care center.

Sharp Edges

That plaza, a welcome bit of sun-splashed public space, echoes in its toughness the gritty south-of-Market-Street surroundings: trendy industrial-look lofts jammed against methadone clinics and check-cashing outlets. The sharp edge of the shading pergola, with its pistonlike, tubular-metal braces, looks as if it could impale an invading tank.

For all its architectural showmanship, the design painstakingly coordinates strategies that harvest sun and breezes to replace electric lighting and air-conditioning. The use of the metal panels came out of an emerging discipline called ``building physics,'' provided here by Ove Arup & Partners, a London-based international engineering giant.

Through a building-physics analysis, those panels were designed to retain accumulated solar heat as a thermal blanket over the building's facade. When that air warms, it floats upward, coaxing cooler air through the building via windows that open automatically when instructed by sensors. The result is free air-conditioning.

By carefully controlling unwanted glare on all sides, most people can work using the daylight from the floor-to-ceiling glass instead of electric lights. The north side has its own sunshade system, vertical milky-glass fins angled to protect occupants from late-afternoon summer sun.

Windows for All

With its ample daylight, soft breezes and gorgeous city views, the 575,000-square-foot federal building is a more pleasant place to work than today's sealed-up, tinted-glass buildings pumped full of refrigerated air. Even a worker in the ``worst'' seat, only about 25 feet from a window, can grab that precious daylight.

For some San Franciscans, it hasn't been love at first sight. ``Very military-industrial complex,'' commented one passerby on a recent visit. Still, Mayne gives a welcome jolt to a once-charming skyline that decades of knee-jerk populism have pummeled to dumpiness.

Buffed, dream-factory California doesn't interest him. Instead, he channels the heedless kaleidoscopic energy of the Los Angeles flatlands, where skinny palm trees rise amid elevated freeways and billboards, and sun glints off endless lines of car bodies.

Bold Move

The U.S. General Services Administration commissioned this building because Edward Feiner, who recently left his post as the agency's chief architect, had pledged that the government would use the nation's best all-around designers. The agency took a risk with Mayne's gutsy aesthetic, but he delivered not only the environmental regime and visual bravura but an unusually high- quality workspace.

The main elevators stop only at every third floor, which urges people to stroll handsome stairways and engage with each other informally in appealing lobbies. A ``skygarden'' within a three-story-high hole poked high in the building is transected by slick little bridges. It imbues the prosaic coffee break with urban theatricality and drop-dead views.

While the federal building imports technologies and concepts developed in Europe more than a decade ago, it's revolutionary by U.S. standards -- and far ahead of the low-ambition ``greening'' prevalent in the private sector that touts bamboo flooring as an eco-credential. The G.S.A., Mayne and Arup have shown that U.S. buildings can set a much higher standard for workplace quality at considerably lower cost to the environment.

(James S. Russell is Bloomberg's U.S. architecture critic. The opinions expressed are his own.)

To contact the writer of this story: James S. Russell at jamesrussell@earthlink.net.

Last Updated: March 2, 2007 00:07 EST