Building an ADU in the Inland Empire? Verify Local Requirements

Southern California ADU builders got a break: fees now applied only above 750 sq-ft, a change expected to save thousands of dollars.
New rules aimed to ease townhouse approvals on small vacant or long-unoccupied single-family lots, creating starter-home options and requiring faster local approvals when projects qualify.
In the LA metro, where ~74% of land was single-family-only, the update opened a narrow path for multiple for-sale townhouses on qualifying lots.
Another change asked cities for early good-faith infrastructure estimates, helping Southern California builders spot sidewalk, utility, or traffic-signal costs before construction advanced too far.
Even with new tools, results may vary because many provisions stay narrow, local size limits remain, and cities still keep public-safety exceptions.