Situated off rocky Yerba Buena Island and connected to the Bay Bridge, 400-acre Treasure Island, formerly the site of the 1939 International Exposition and home to a U.S. Navy base, is centrally located in San Francisco Bay, yet strangely desolate. A major urban renewal project should change that significantly over the coming decades.

Both Yerba Buena and Treasure islands are part of a major project, years in the making, though the bulk of the redevelopment will occur on Treasure Island. The manmade island has presented a formidable set of challenges to redevelopment efforts, not least being the handover of the land from the Navy, scores of public meetings, and the need for major toxic cleanup and seismic upgrades.

This past December the project cleared a significant hurdle: The development plan received preliminary approval from the San Francisco Board of Supervisors. The approval paves the way for the design and development team (chosen through an RFQ issued in 2001) to finalize a binding contract for the project. With overall completion of the development scheduled for 2022, the first new residents are expected to begin moving in by 2013. Costs are projected at $1.2 billion, of which $500 million will be private investment and $700 million city bonds. The development team includes San Francisco’s Kenwood Investments and Wilson Meany Sullivan, along with Lennar Corporation, headquartered in Miami; the San Francisco office of Skidmore, Owings & Merrill will complete the design with SMWM and CMG Landscape Architects, both San Francisco firms.

At the heart of the environmentally sustainable scheme, which includes green elements ranging from runoff-filtering wetlands to green skyscrapers, is 300 acres of open space that include—in addition to the wetlands—an ecological education and art park, a shoreline park at the island’s edge, playgrounds, and a 20-acre organic farm. Diagonal rows of planted trees will provide protection from the island’s strong winds, and a wind farm—another integral piece of this sustainable “working landscape”— takes advantage of those same conditions.

The scope, scale, and visibility of this dramatically situated project make it one of the highest-profile urban redevelopments in the country,and certainly one of the largest development plans in San Francisco’s history.

The plan’s compact footprint (it occupies only a quarter of the island’s area) will be built in phases. The residential zone will house some 13,500 residents in approximately 5,900 units (about 30 percent of which will be affordable) arranged in a variety of massings: high-density, low-to-midrise blocks of townhouses, flats clustered around neighborhood open spaces, and residential towers of around 14 stories. A new street grid, aligned with the wind-shielding rows of trees, offers a “richer pedestrian experience than the typical Cartesian grid,” said SOM partner Craig Hartman.

The new island skyline centers on a slender “campanile-like” central tower of 60 stories, accompanied by four 40-story towers. These are concentrated at the island’s urban core, which incorporates a new ferry terminal and an adjacent retail, cultural, and commercial district, served by a parking system designed to encourage car-free living. Pedestrian and bike-friendly neighborhoods are grouped so that most are no more than a ten-minute walk from the ferry terminal.

The terminal, nestled into the island’s western “cityside,” about a ten-minute ferry ride from mainland San Francisco, features a curving canopy designed with advanced digital wind modeling. According to Hartman, the terminal’s roof panels will be configured as articulated scales that “diffuse rather than simply deflect the strong winds.”

The central tower will be supported by a sophisticated structural exoskeleton that frames an optimal amount of glass for the exterior. Dubbed the Sun Tower in reference to the island’s former Tower of the Sun— a 400-foot-tall structure that was the first major landmark of the original exhibition grounds—the building will tap into geothermal energy. A series of glass light shelves clad in transparent photovoltaic film covers the building envelope, while a glass sky garden crowns the building.

As is typical of projects this large, there will likely be a selection of other architects involved in fleshing out the plan. Hartman imagines that a range of buildings will be designed by some of the Bay Area’s best design talent. “The intent here,” Hartman said, “is to make this a new national model for what a wholly sustainable community can be about.”