Insights
Accessory dwelling units, lot splits and the state legislation that has reshaped what a residential parcel can carry.
SB 9 is the California law that opened a state level path to a lot split, and to more than one home, on many single-family parcels. Whether you can still use it on a given property depends on eligibility conditions, on how the local ordinance implements it, and on the legal status of the law at the time you apply.
Read What is SB 9, and can you still split a lot in California?
Usually yes, but not automatically. State law has narrowed what cities may prohibit, so most single-family lots in California can accommodate an accessory dwelling unit. What stops real projects is site specific: setbacks, fire access, sewer or septic capacity, easements, utility service, historic overlays and recorded covenants. Confirm those and the current local ordinance before you design.
Read Can you build an ADU on any single-family lot in California?
Most ADUs in California cost roughly $150 to $700 per square foot all in, with garage conversions at the low end and detached new construction at the high end. A small unit still needs a full kitchen, a bathroom, its own systems and its own utility connections, so those fixed costs spread across far less area.
Read How much does it cost to build an ADU in California?
