San Francisco’s Efforts to Block Duplexes Could Force It To Allow Skyscrapers Instead

In a rather genius gambit, San Francisco politicians are warming to the idea of preserving single-family-only zoning in practice by completely abolishing it on paper.

At a Monday meeting of the San Francisco Board of Supervisors’ Land Use and Transportation Committee, supervisors considered three different proposals to legalize four-unit homes (fourplexes) across the city’s residential neighborhoods.

The leading proposal from Supervisor Rafael Mandelman—supported by the city’s Planning Department and Committee Chair Myrna Melgar—is a seemingly ambitious plan to abolish existing single-family zoning citywide and allow four-unit homes everywhere and six-unit homes on corner lots.

“San Francisco continues to struggle to produce new housing units to meet demand,” said Mandelman at Monday’s “fourplexpalooza” meeting. “In this context density restrictions do not make sense.”

In addition to legalizing fourplexes citywide, Mandelman’s bill wouldn’t place any affordability requirements on the new units produced. People could sell or rent them at whatever the market will bear. That earned him some criticism from Supervisors Gordon Mar and Ahsha Safai.

Both have proposed fourplex bills that would keep single-family-only zoning on the books. Instead, they’d create special density bonus programs that allow people to build four-unit homes on single-family lots in exchange for selling or renting some or all of the new units out at below-market rates.

The lack of affordability requirements in Mandelman’s bill earned him some criticism from Mar in particular at Monday’s meeting, who accused him of offering a “neoliberal” proposal that wouldn’t produce the lower-income housing the city really needs.

Mandelman countered that he wasn’t a neoliberal, but he was a realist who recognized that developers and homeowners weren’t going to convert new housing into fourplexes if they had to sell them at a steep discount. (On that point, he’s in agreement with both city planning staff and housing policy experts.)

The fact that Mandelman’s proposal abolishes single-family zoning and forgoes price controls on new units seems to make it the most free market of the fourplex legalization bills on offer, right? Not so fast.

Because his bill eliminates single-family zoning, it nullifies California’s recently passed S.B. 9. That law allows property owners to split their single-family zoned lots in two and build a duplex on each half—permitting four homes where only one could go previously.

S.B. 9 also requires local governments to “ministerially approve” these lot splits and duplexes—meaning city officials can’t apply onerous conditions on projects and neighborhood NIMBYs can’t delay them with endless public hearings and appeals.

But if San Francisco gets rid of its single-family zoned lots, as Mandelman is suggesting, then S.B. 9 can’t apply anywhere.

One might ask “what’s the big deal?” given that Mandelman is ultimately proposing to legalize the same number of units per lot (and even more on corner lots).

The trouble is that while his bill replicates the zoning reforms of S.B. 9, it ditches its equally important process reforms. The law’s requirement that duplexes be ministerially approved would be a huge improvement over San Francisco’s existing permitting process.

San Francisco is an “extreme outlier” in how long it takes to approve new housing, according to one recent study prepared for the California Air Resources Board. That study, as reported by the San Francisco Examiner, found that it took the city an average of 27 months to approve new projects. That’s the longest of any city in California. In neighboring Oakland, it took just five months on average to approve a new project.

A big reason for these extraordinary approval times is a feature of San Francisco’s permitting process called discretionary review, which gives the city’s planni