Five California cities have won a lawsuit against the state over SB 9, a law passed in 2021 that effectively abolished single family zoning statewide.

A Los Angeles County judge has ruled that the California law abolishing single-family zoning across the state is unconstitutional. Passed in 2021, SB 9 allowed single-family homeowners to split their lots in two and build a home on each or convert their homes to duplexes, regardless of local zoning. The ruling means SB 9 now cannot be applied in any of the five Southern California cities — Redondo Beach, Carson, Torrance, Whittier, and Del Mar — that sued the state, and the judge is expected to produce a ruling next month that will strike down the law statewide, reports Kate Talerico for the Marin Independent Journal.
“At the heart of the case is local authority and what gives the state the right to interfere. In California, the constitution requires that state laws impeding cities’ local control must demonstrate a reasonable relationship between the legislature’s stated intention and the design of the law,” Talerico writes. The stated intention for SB 9 was improving housing affordability, but the judge ruled that the legislature’s intention doesn’t match up with the design of the law because the law doesn’t require any of the resulting units to be priced below market rate.
Advocates for local authority over land use and zoning consider the ruling a big win. Housing advocates say the judge’s definition of housing affordability was extremely narrow. Talerico reports that a simple clean-up bill to SB 9, like the one proposed in the legislature last year, could “render the Los Angeles court’s decision moot.”
FULL STORY: LA judge strikes down California lot-splitting law

Maui's Vacation Rental Debate Turns Ugly
Verbal attacks, misinformation campaigns and fistfights plague a high-stakes debate to convert thousands of vacation rentals into long-term housing.

Planetizen Federal Action Tracker
A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

In Urban Planning, AI Prompting Could be the New Design Thinking
Creativity has long been key to great urban design. What if we see AI as our new creative partner?

King County Supportive Housing Program Offers Hope for Unhoused Residents
The county is taking a ‘Housing First’ approach that prioritizes getting people into housing, then offering wraparound supportive services.

Researchers Use AI to Get Clearer Picture of US Housing
Analysts are using artificial intelligence to supercharge their research by allowing them to comb through data faster. Though these AI tools can be error prone, they save time and housing researchers are optimistic about the future.

Making Shared Micromobility More Inclusive
Cities and shared mobility system operators can do more to include people with disabilities in planning and operations, per a new report.
Urban Design for Planners 1: Software Tools
This six-course series explores essential urban design concepts using open source software and equips planners with the tools they need to participate fully in the urban design process.
Planning for Universal Design
Learn the tools for implementing Universal Design in planning regulations.
planning NEXT
Appalachian Highlands Housing Partners
Gallatin County Department of Planning & Community Development
Mpact (founded as Rail~Volution)
City of Camden Redevelopment Agency
City of Astoria
City of Portland
City of Laramie