San Francisco already taxes the biggest real-estate sales at some of the highest transfer-tax rates in California. Proposition I asks voters whether half of that money from deals of $10 million or more should be locked into affordable housing rather than flowing into the city's discretionary General Fund.
What the measure would change
Under today's rules, transfer-tax revenue from every sale — including the 5.5% bracket on properties from $10 million to $25 million and the 6% bracket above $25 million — goes into the General Fund. The League of Women Voters of San Francisco's nonpartisan guide says Prop. I would keep half of the tax on those high-value transfers for general city needs and send the other half, labeled a House SF Tax, into a new House SF Fund that can be spent only on listed housing purposes.
SPUR's analysis describes the same split in mechanical terms: cutting the existing rates on $10 million-plus sales in half, then imposing a matching House SF tax so the total rate paid stays the same while half of the dollars are restricted. The fund would dedicate at least 60% to affordable housing production (with at least half of that slice reserved for alternative models such as social housing, community land trusts and limited-equity cooperatives), at least 25% to preservation and acquisition, at least 10% to tenant protections and homelessness prevention, and up to 5% to administration, according to SPUR, GrowSF and the League guide.
Certain newly built multi-unit residential buildings would get an exemption on the first sale, the League and GrowSF note. Prop. I would also sharply limit the Board of Supervisors' power to lower, suspend or repeal the transfer tax without another public vote. It needs a simple majority.
Where the money would come from — and what it costs the budget
The San Francisco Controller's Office estimates the measure would redirect about $114 million a year beginning in fiscal 2026-27 from the General Fund into the new fund, rising above $124 million by 2030, SPUR reports, citing the controller's June 2026 revenue letter. GrowSF puts the General Fund diversion near $120 million a year and notes the controller calls the new fund the city's 24th voter-mandated funding requirement. Transfer-tax collections swing with the market, so the housing stream would be volatile even if the rates stay high.
Supporters listed by the League include the Affordable Housing Alliance, the San Francisco Tenants Union, United Educators of San Francisco, SEIU 1021 and Democratic Socialists of San Francisco. They argue the measure finally locks in a 2020-era promise to use luxury-sale taxes for housing and that a first-sale break for new multifamily projects would encourage construction. Opponents include the San Francisco Taxpayers Association and the San Francisco Building and Construction Trades Council, who warn that emptying the General Fund will squeeze police, fire, parks and other services. SPUR recommends No for that reason; GrowSF also opposes.
How it landed on the ballot — and how it interacts with Prop. J
Prop. I is a citizens' initiative. GrowSF says proponents Scott Feeney and Tuesday Rose Thornton, tied to the San Francisco Democratic Socialists of America chapter, filed it, and that the campaign submitted more than 20,000 signatures on July 2, 2026. The League lists Yolanda Porrata, Thornton and Feeney as proponents and notes that if Prop. I and Proposition J conflict, Prop. I prevails — though the guides say the two mostly address different pieces of the transfer-tax code. For more November contests, see our Nov. 3, 2026 Bay Area election guide.