California AG looks to revive law allowing single-family lot splits

California Attorney General Rob Bonta is fighting for Senate Bill 9, a state law that allows single-family lots to be split for the development of duplexes.

The attorney general has appealed a decision from the California Superior Court, which struck down the legislation and ruled it unconstitutional, according to a notice of appeal filed last week.

“We firmly believe that SB 9 is constitutional as to every city in the state,” Bonta said in a statement. 

In 2022, five Southern California cities — Carson, Redondo Beach, Torrance, Del Mar and Whittier — sued the state, claiming SB 9 interfered with local governance, according to court records. 

The legislation required all California cities “ministerially approve” applications to divide a single-family lot into up to four units. That means any applications that came in had to be approved regardless of zoning. 

The cities argued the law took away power to reject plans. 

The cities got a win in April, when Los Angeles Superior Court Judge Curtis Kin ruled that SB 9 did not actually ensure access to affordable housing. 

The law did not “require, promote or incentivize” that units built on divided single-family lots actually be classified as affordable, Kin said in his order. 

Passed in 2021, SB 9 has become a point of contention in the NIMBY versus YIMBY debate. The legislation was supposed to boost housing availability across the state by expediting the construction of housing in single-family neighborhoods. However, a year after it came into effect, a UC Berkeley report found the impact of the law had been “limited.”