Zoning Glossary

SB 9

Senate Bill 9 (SB 9) is a California state law, effective January 1, 2022, that requires cities to ministerially approve two related actions on qualifying single-family parcels: splitting the lot into two separate parcels, and building up to two units on each resulting parcel. The combination of these provisions allows multiple housing units on what was previously a single-unit lot, making SB 9 one of the most significant expansions of residential development rights in California history. The law applies in urbanized areas and excludes properties in historic districts, coastal zones, high fire hazard severity zones, earthquake fault zones, and floodplains.

ADU

In Practice

SB 9's lot split provision is what makes separate sale of newly created parcels possible — once a lot is divided into two independent legal parcels, each can be sold, financed, or developed independently. The applicant for an SB 9 lot split must certify an intent to occupy one of the resulting units as a primary residence for a minimum period defined in the law. Cities cannot require discretionary review or public hearings for qualifying SB 9 applications; approval is administrative if the objective eligibility criteria are satisfied.

Source: Lot Splitting Laws: Which States Allow It? · Verified June 1, 2026

Source: PropertyZoned Zoning Guide — Lot Splitting Laws: Which States Allow It?. Last verified June 1, 2026.

Last updated: June 1, 2026

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SB 9

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