San Francisco owns at least 147 usable public properties that could be suitable for affordable housing development, according to a new report from the Board of Supervisors' Budget and Legislative Analyst's Office. The finding lands as the city has reached just 12% of its state-mandated goal to build 82,000 housing units by 2031, with at least 12,600 affordable units already stalled for lack of funding.
The report, first detailed by The San Francisco Standard, reviewed properties owned by the city, the San Francisco Unified School District, and the San Francisco Community College District, identifying 147 properties warranting closer review for affordable housing, consolidation, sale, or other uses. The Port of San Francisco alone manages 32 of the identified properties, per the same report. Among the standout sites is 170 Otis Street, current home to the Human Services Agency's headquarters, which the analyst's office says could accommodate about 270 homes once the agency moves out.
A Seismic Deadline Forces the City's Hand
The Human Services Agency headquarters at 170 Otis Street is in poor condition and at risk of partial or total collapse in a major earthquake, according to the Standard's report, and the agency plans to move out by 2029. That timeline lines up with a 225,883-square-foot lease expansion at 1455 Market Street that the Board of Supervisors approved in April 2025 to consolidate city departments, a move that will let the Human Services Agency vacate the building, as reported by The Registry Northern California Real Estate. Structural evaluations have designated 170 Otis Street a high-risk Seismic Hazard Rating 4 building, per Patch.
SFMTA owns most of San Francisco's parking lots and reviewed about 90 properties under a program adopted in 2025, the Standard's report notes. The transit agency is working with a consultant to rank properties by potential housing, transit ridership, and revenue generation. Fire and police departments could also consolidate some stations, while housing above city recreation centers would require a voter-approved charter amendment, per the same account.
Why the 2002 Reporting Law Went Quiet
A 2002 law requires most city departments to report surplus or underutilized properties annually so they can be evaluated for potential affordable housing development, but the law has flagged no property since 2017. No department volunteered land between fiscal 2017-18 and 2025-26, according to the Standard's report. San Francisco's Surplus Public Lands Ordinance, enacted that same year and modified by voters through Measure K in 2015, exempted key landholding entities including SFMTA, the Port, and the Recreation and Parks Department, according to the San Francisco Planning Department. Measure K was designed to prioritize underutilized public land for 100% affordable housing developments.
The Port of San Francisco, the municipal transportation authority, and the Recreation and Parks Department are all exempt from the 2002 property-reporting law, which the analyst's office says explains why so few sites have surfaced for review in recent years. The Budget and Legislative Analyst's Office called for collaboration among the Port, SFMTA, the school district, and other agencies exempt from the 2002 law, along with dedicated staff to carry out public-land planning.
Supervisor Wants a Single Agency in Charge
District 3 Supervisor Danny Sauter, who requested the report, said the city's unused land represents both a significant opportunity and limited action so far. The Budget and Legislative Analyst's Office recommended the Board of Supervisors adopt a citywide policy on using public land and that a single agency oversee the review process going forward.
Sauter pointed to New York City as a model worth studying. Mayor Zohran Mamdani created a task force to identify public sites capable of supporting at least 25,000 new housing units over the next decade and established a fast-track process for developer selection, according to Hoodline's earlier coverage of the initiative. Sauter said San Francisco needs a similar public-land commitment through legislation and the mayor's office, adding that clear ownership, specific goals, and enforced timelines are essential.
Land Is Only Part of the Cost Problem
Even with more sites identified, the analyst's office cautioned that land accounts for only about 10% of the cost of building an affordable housing unit, meaning free parcels alone won't close the funding gap. Officials from the Mayor's Office of Housing and Community Development reported in early 2024 that building a single unit of affordable housing in San Francisco costs over $900,000, requiring roughly two-thirds of project financing to come from state and federal subsidies, according to Mission Local. Between 2018 and 2023, San Francisco affordable housing projects secured $2.6 billion in state and federal funds compared with $1.2 billion in local funds, the outlet reported.
Voters approved Proposition A in March 2024, authorizing $300 million in general obligation bonds for the construction, acquisition, and rehabilitation of affordable housing without raising local property tax rates, with $240 million to $258 million of that set aside for low-income housing targeting households earning up to 80% of area median income. The Budget and Legislative Analyst's Office recommended San Francisco treat its real estate holdings as a strategic asset, noting that the sale or lease of city properties could provide new sources of funding for affordable housing rather than just donated sites.
Potrero Yard Shows What's Possible — and What Could Go Wrong
One project offers a glimpse of what joint public development can look like. An earlier plan for the 4.4-acre Potrero Yard called for a rebuilt bus facility and up to 465 homes. After that larger housing plan was scaled back, up to 100 affordable units are now planned adjacent to the facility rather than above it.
But that transit-oriented model faces its own headwinds. San Francisco transit officials warned in September that SFMTA faces structural budget deficits that could force up to 30% in Muni service cuts, according to the San Francisco Public Press, a threat that could undermine housing plans built on city parking lots. Local advocates have placed Proposition H on the November ballot to raise up to $184 million annually in parcel taxes to protect transit operations, per the same report.
The report's release comes as the city works through the broader implications of Mayor Daniel Lurie's Family Zoning Plan, which took effect in January and ended single-family-only zoning citywide, permitting multi-family residential density across northern and western neighborhoods, according to the San Francisco Planning Department. That rezoning removed a zoning barrier that once surrounded city-owned parcels in historically low-density districts, though whether it will be enough to unlock the 147 identified properties remains an open question for the Board of Supervisors to answer.
