Mayor Lurie and Supervisor Mahmood Launch BUILD Act to Slash Transfer Tax, Unlock 50,000 Stalled Homes

San Francisco's mayor and Supervisor Mahmood unveiled the most significant transfer-tax reversal since 2020, pitching a revenue-neutral package to roll back the nation's highest property-transfer levy on large developments while closing a growing loophole on commercial foreclosures. With more than a dozen trade unions, the Chamber of Commerce and fellow supervisors at their side, the coalition argued the city's own tax policy has become the primary obstacle to building the housing it approved years ago.

• BUILD Act would return transfer-tax rates on large multifamily and commercial projects to pre-2020 levels, saving more than $32,000 per unit in construction costs

• Roughly 50,000 approved housing units sit unbuilt citywide, with 34,000 tied up in major multi-phase projects representing tens of thousands of union job-years

• November ballot measure targets a foreclosure-transfer loophole that lets high-value commercial properties dodge the tax at unprecedented rates

• Coalition pledges a sustainable affordable-housing financing plan within three months, pairing the tax cut with a concrete replacement strategy

• $180 million in union pension capital at the 1111 Sutter project alone illustrates how retiree savings are directly tied to whether stalled developments proceed

Why it matters: San Francisco doubled its real-property transfer tax on large transactions in 2020 to 6% — the highest rate in the country — to fund affordable housing. Instead, capital fled, projects stopped penciling out, and the construction workforce lost years of steady employment. The BUILD Act is the city's first major attempt to reverse course.