Treasure Island Development Group

When the U.S. Army Corps of Engineers constructed a 576-acre man-made island off the coast of San Francisco between 1936 and 1937, local rumor had it that they were stirring up more than mud, sand, and boulders. The tales of millions of dollars of gold dust gave the landmass the name it still bears today: Treasure Island.

Originally built for the 1939 World’s Fair on the shoals of the neighboring Yerba Buena Island in San Francisco Bay, Treasure Island served as a naval base during World War II. Since being decommissioned in 1996, it’s become a tourist destination (thanks to its amazing views of the city skyline) and a site for affordable housing.

Treasure Island’s latest reinvention will offer a new kind of riches: a multibillion-dollar neighborhood redevelopment that will ultimately boast 8,000 new homes and condos (2,000 of which will be designated as affordable housing), as well as 500 new hotel rooms and more than 550,000 square feet of commercial space. In the housing- and space-strapped Bay Area, these additions are crucial. What will this project mean for San Francisco, notorious for its single-family zoning and challenging housing market?

The number of affordable units included in the project is “nothing to sneeze at,” says Jasper Rubin, an urban studies professor at San Francisco State University’s School of Public Affairs & Civic Engagement. “The new affordable housing [will] be substantial for a single development project,” he says.

A complicating factor of this decades-in-the-making redevelopment is radioactive material left behind by the U.S. Navy. Following WWII, the military used the island to conduct training academies in which radiation-safety officers were asked to handle isotopes like radium-226 and cesium-137. While the navy made an official statement in 2020 that all accessible areas of Treasure Island are “safe to the public and confirmed to have no radiation above naturally occurring background levels,” Business Insider reported that same year that some residents who have lived on the island for decades, as well as their children, have experienced health issues like chronic coughs and cancer.

Nevertheless, the city deemed Treasure Island’s redevelopment safe enough, and important enough, to allow $6 billion in investment from developers, collectively called Treasure Island Community Development, to go forward. Planning for the project started in the early 2000s, and in 2005 the developers hired Skidmore, Owings & Merrill (SOM) to join the design team and create a master plan. Craig Hartman, FAIA, of SOM describes some previous plans for development of the island as more “suburban-style schemes” that allowed for only about 3,000 units of housing.

“The charge was, ‘Can you put some tall buildings here to increase the density?’” Hartman says. SOM, however, took things a step beyond simple density. “The goal that we took forward was to try to find ways to make this synthetic, man-made island, which has been occupied by the navy for 50 years or so, and make it kind of a model of sustainability,” Hartman says.

SOM started by factoring in how sun and potentially high winds would impact walkways and buildings on the island. The firm’s aim was to make the development compact and interwoven with the natural environment, especially where it came to maximizing sunlight in public places.

Ultimately, SOM developed a master plan that prioritized three neighborhoods organized around a town center and a ferry terminal—a layout “intended to encourage walking, bicycling, and using mass transit,” according to the project description. Approximately 300 acres of the island will be set aside for open space, and all new landscaping will use native species. The firm also touts grey-water recycling, an extensive composting program, and the use of renewable grid-source power to meet the island’s energy needs. Due to regulatory approvals processes, Hartman says, “There were a lot of challenges in making this happen.”

“One of the driving ideas was to create a human-scale place,” Hartman says. “The idea was to try to create this urban fabric in the four-to-eight-story range with high rises, strategically located to mark specific, very important pieces of social interaction on the island," to make Treasure Island sustainable “environmentally, economically, and socially,” he says. It was important that the master plan prioritize walkability, which SOM accomplished by placing density near the island’s transportation hub. At least 80% of the island’s eventual population will be within a 5-minute walk of the hub, and none of the homes will be more than 15 minutes away by foot.

“It meant making streets that were highly walkable and shared, so that vehicles could use the streets, but they were pedestrian-favored,” Hartman says. As the project description concludes, “The scheme represents San Francisco’s best opportunity to accommodate population growth with a minimal ecological footprint.”

Thoughtfully Designed Affordable Housing

Due to the single-family zoning in much of San Francisco, new housing projects like the ones on Treasure Island are tough to have developed and approved. Since the 1960s, the city—and the surrounding Bay Area—has enacted strict regulations, including not allowing buildings over 40 feet tall in most of the city and ensuring an easy process for neighbors looking to block new developments via "conditional" zoning. In 2021, the American Housing Survey estimated that nearly three-quarters of all residential land in the city is devoted to single-family homes and duplexes.

The first phase of housing on Treasure Island, about 1,500 units, is in the final stages of completion. The second parcel is expected to open by next year, and developers anticipate completion of the entire master plan by 2036. Of the 2,000 affordable units that the island will ultimately hold, 105 will be in the Maceo May Apartments, designed by Seattle-based firm Mithun (in partnership with San Francisco veteran services organization Swords to Ploughshares) and completed in February. The structure was purpose-built for formerly unhoused veterans, some of whom had previously been residents of Treasure Island, and families with children. The all-electric design emphasizes modular construction to ensure that the building could be completed on a shortened timeline.

The Maceo May complex was also designed with trauma-informed practices in mind, emphasizing features like integrated natural elements and thoughtfully rendered open spaces. “We were able to draw on clinical studies of architectural design that can support those with PTSD,” says Hilary Noll, AIA, of Mithun, who worked as an architect on the project. Noll and colleague Dan Solomon, FAIA, prioritized views for all residents, as well as easy access to nature via a community park and island trail network.

The seven-story, 138-unit Star View Court, another affordable housing complex included in phase one of Treasure Island’s development, is currently under construction. A collaboration between Bay Area nonprofits Mercy Housing and Catholic Charities, the completed complex will offer 23 units of replacement housing for existing Treasure Island residents and 71 units of relocated housing for an existing project run by Catholic Charities. The remaining 43 units will be affordable for households earning between 30% and 100% of the area median income. As an October 2022 story from news outlet Yimby San Francisco reported, Star View Court became the first-ever development to receive backing from the California Housing Accelerator, a state program that seeks to close financing gaps in affordable housing projects. Star View Court was financed through the state budget using money from the federal Coronavirus State Fiscal Recovery Fund.

“We were brought in during schematic design, once we had a basic picture of what we were going to be doing,” says Eric Robinson, AIA, of Paulett Taggart Architects, project architect on Star View Court. He and other firm architects met with future residents of the complex to answer questions and address concerns. “We took it to the next level in terms of giving [residents] a sense of what it was going to look like, what the services and amenities would be,” he says. On the day that construction workers broke ground on the complex in July 2022, San Francisco mayor London Breed called the complex “just the beginning.”

More Density to Come?

In Greater San Francisco, the mood surrounding the Treasure Island build-out seems tentatively hopeful. As cranes rise above the island, a new community takes shape, and a new ferry route makes transportation to and from the mainland easier, this optimism seems warranted.

However, for the city to continue to innovate to meet the need for housing beyond Treasure Island, it’ll have to be creative. “San Francisco is essentially built out,” says Rubin, of San Francisco State University. “There are probably no sites or areas left in San Francisco proper for this scale of development, so for the city to respond to its dire need for new housing will take different strategies.” He emphasizes that the dense residential projects are what the city, and the Bay Area as a whole, desperately needs more of.

“Projects like Treasure Island could be beneficial in other parts of the Bay Area, especially as an alternative to traditional suburban development,” Rubin says.

Robinson, of Paulett Taggart Architects, isn’t ruling out a move to the island himself.

“I live in Berkeley and our second daughter just went off to college,” he says,” and I’ve playfully said to my wife, ‘Would you ever consider living on Treasure Island?’ I expect it to be a really nice place, and I see all the benefits of it.”