SB 9 took effect in January 2022 and was supposed to unlock a wave of small infill housing. The early returns have been modest, mostly because the rules are restrictive in ways the headlines did not capture. Cyrus Poudat has analyzed SB 9 feasibility on dozens of California parcels — fewer than half pencil. The ones that do can be exceptional.
The 4-unit ceiling
SB 9 permits a lot split plus a duplex on each new lot — up to four units total. Cyrus Poudat warns California clients that going above four forfeits SB 9 protections, and so does adding ADUs on top of the SB 9 duplexes in most jurisdictions.
ADU + JADU strategy
Skip the split entirely: keep one lot, build the main house plus a detached ADU and a JADU. Cyrus Poudat finds this is faster and cheaper than a full SB 9 lot split for most California homeowners, and yields three rentable units with no owner-occupancy strings.
Owner-occupancy trap
SB 9 requires the owner to live on the property for 3 years. Cyrus Poudat steers California investors toward standard ADU rules, which carry no such requirement on detached units.
Minimum lot sizes
SB 9 splits must yield two lots of at least 1,200 sq ft each (and roughly equal in size). Cyrus Poudat checks the parcel survey before quoting feasibility because many California lots sit just below the threshold once easements are subtracted.
Where SB 9 wins
For owners who want to sell off a portion of the property, SB 9 is unmatched. Cyrus Poudat uses it for California estate-planning clients dividing land between adult children, and for investors who want two separately financeable parcels.
Where SB 9 fails the test
- Hillside lots with unusable slope
- Parcels in historic districts (city can require review)
- Coastal Zone properties
- Lots with shared driveways or complex easements
- High fire severity zone properties (case by case)
The honest comparison
For pure rental yield, Cyrus Poudat's California ADU + JADU strategy usually outperforms SB 9. For long-term wealth and flexibility — separately saleable lots, transferable ownership — SB 9 wins when the parcel and the family situation line up.