A Los Angeles County judge found that charter cities aren’t subject to Senate Bill 9, the 2021 “duplex” law that allows up to four homes to be built on a lot in single-family neighborhoods.

The law fails to accomplish its stated purpose of creating more affordable housing, and therefore, doesn’t meet the high bar of overriding local control over zoning, Superior Court Judge Curtis Kin said in a ruling released Wednesday, April 24.

SB 9 “is neither reasonably related to its stated concern of ensuring access to affordable housing nor narrowly tailored to avoid interference with local government,” Kin wrote.

The ruling applies only to the state’s 121 charter cities, not to more than 400 “general law” cities and counties operating without their own charters.

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Seen as an effective end to single-family zoning in California, the law allows lot splits in suburban neighborhoods, with one home and one “accessory dwelling unit” (or granny flat) on each new lot — replacing one home with up to four.

The law sought to address soaring housing costs by giving renters and working families greater access to neighborhoods they couldn’t otherwise afford.

The state Legislature also found that SB 9 should apply to charter cities, which enjoy greater autonomy, because affordable housing is a “matter of statewide concern.”

But five Southern California cities — Redondo Beach, Torrance, Carson, Whittier and Del Mar — sued to block the law, arguing it violated the state constitution that gives the state’s “home rule” cities the right to govern their own “municipal affairs.”

Kin wrote that Attorney General Rob Bonta and the state housing department failed to prove that SB 9 would increase the number of homes affordable to low income families — “especially in economically prosperous cities,” he wrote.

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Asked if the state plans to appeal the ruling, the Attorney General’s Office issued a terse statement: “We are reviewing the decision and will consider all options in defense of SB 9.”

All California cities and counties operate under California “general law.” But charter cities effectively operate under their own constitutions that supersede state laws on local affairs, such as planning and zoning.

The legislature, can override city charters, however, in matters of statewide concern, such the lack of affordable housing.

“The Legislature finds and declares that ensuring access to affordable housing is a matter of statewide concern and not a municipal affair,” SB 9 states. “Therefore, … (this law applies) to all cities, including charter cities.”

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But the law does nothing to guarantee more affordable housing, Kin wrote. At the same time, he rejected the state’s argument that SB 9 promotes housing affordability at lower income levels by increasing the overall housing supply.

” ‘Affordable’ refers to below market-rate housing,” Kin wrote. The state gave “no evidence to support the assertion that the upzoning permitted by SB 9 would result in any increase in the supply of below market-rate housing.”

Redondo Beach City Attorney Michael Webb hailed Kin’s ruling, saying SB 9 amounts to a “kind of trickle-down economics applied to zoning.”

“It was a massive upzoning that would have just led to more market-rate housing, more million-dollar townhomes,” Webb said. “In Redondo, we support affordable housing, but we don’t support one size fits all, top-down laws that disrupt communities and don’t … lead to more affordable housing.”