The mixed-use transformation of an island overlooking San Francisco’s Bay Bridge is taking further shape as the city ramps up housing development to meet lofty construction goals.

San Francisco-based developers Wilson Meany and Stockbridge Capital Group are beginning to prelease Isla House, the first high-rise apartment complex developed as part of the Treasure Island Community Development project. The 22-story, 250-unit project is slated to open in August before developers kick off the next wave of housing development for the former U.S. Naval Base site.

The project, a public-private partnership comprised of the City of San Francisco, Wilson Meany, Stockbridge Capital Group and Lennar Corporation, aims to transform the island into 8,000 homes, 300 acres of new parks and a mix of retail uses over an undisclosed timeline. The project cost is estimated to run some $1.5 billion over the next 20 years.

The development is one of the more unique ways the city is tapping underutilized land for housing projects as the region aims to meet a state mandate to build 80,000 housing units by 2031, the highest for the Bay Area and among the largest requirements in the state of California.

San Francisco issued only 1,136 residential building permits in 2023, its lowest total since the Great Recession in 2007, when only 779 permits were issued, according to data from the U.S. Department for Housing and Urban Development. Just 110 units have been built in downtown San Francisco in the past 10 years, according to CoStar data.

Other projects currently under construction on Treasure Island include the 138-unit Star View Court, the 178-unit Hawkins apartment complex, and the 148-unit Portico.

The roughly 400-acre Treasure Island was built for the 1939 Golden Gate International Exposition, a World's Fair event to celebrate the opening of the San Francisco-Oakland Bay Bridge and the Golden Gate Bridge.

Plans to transform the island kicked off in 1990 when the city took over the site; after decades of discussion, the city formed Treasure Island Community Development in 2011.

Developers have built 1,000 housing units over the past three years, with an additional 1,000 units planned as part of the second phase.

While most of the funding has been secured privately by the developers, San Francisco has also pitched in funds such as providing $43.7 million for the 104-unit Maceo May apartment complex that opened last year.

Mayor London Breed and County Supervisor Matt Dorsey introduced legislation in April to fast-track financing for the second phase, according to previous reporting by Costar News.

The legislation would provide $115 million in financing from the city’s general fund for the next 1,000 units, of which 250 will be affordable for those making a certain portion of the area median income. The funds would also finance a 240-bed behavioral health center and restoration of historical buildings and public parks.

Other housing-focused redevelopments underway in the region include Brookfield Properties' plans to transform parts of a large suburban mall into 3,500 homes, while Irvine-based Five Point Holdings aims to transform the area around Candlestick Park into 7,000 housing units and 3 million square feet of office.

Treasure Island does not face the same level of housing development pushback from residents compared to neighborhoods in the city, according to Robert Sammons, senior market analyst at Cushman & Wakefield’s San Francisco office.

“It’s removed from other parts of the city, thus very few if any NIMBYs are around to voice opposition,” he said, referring to the Not In My Back Yard acronym that represents residents who oppose development near where they live.

These oppositions are typically active in wealthier neighborhoods such as the Marina, Telegraph Hill and St. Francis Wood, according to reports.

A majority of the apartments planned for Treasure Island will be market rate, or roughly $3,000 per month. Rents in San Francisco are among the highest in the nation, according to CoStar data.

Affordable units at the projects, as required by the city, will be cheaper for renters earning less than 80% of the area's median income. About 25 units, or 10%, of Isla House will be designated as affordable.