California ADU Laws

ADU Laws in California (2026)

California state ADU law details, key provisions, preemption status, and recent legislative changes for accessory dwelling units.

Effective Date

2020-01-01

Preempts Local Ordinances

Yes — state law overrides local restrictions

Has State Law

Yes

Statewide ADU Preemption Applies

Verified

State law establishes statewide preemption standards that supersede local regulations. The citation and source below confirm the verified legal basis.

Source:Cal. Gov. Code §66316 – ADU Approval Requirements (null-and-void enforcement) + §66317(a)(3) – 60-day ministerial approval (formerly § 65852.2 (ADU) + § 65852.22 (JADU), repealed by SB 477, 2024)Last verified: 2026-06-18

Key Provisions

  • ADUs permitted by-right on all single-family and multifamily residential lots — no discretionary review allowed · Source

  • JADUs (Junior ADUs) up to 500 sqft permitted within existing residential structures · Source

  • Owner-occupancy requirement eliminated effective January 1, 2020 · Source

  • No setback requirement for ADU replacing existing structure in same footprint · Source

  • 4-foot side and rear setbacks for new detached ADUs · Source

  • No minimum lot size for ADU development · Source

  • Impact fees waived for ADUs under 750 sqft · Source

  • School developer fees waived for ADUs under 500 sqft per §66311.5(c)(3) · Source

  • Ministerial approval within 60 days required · Source

  • ADUs cannot be sold separately from primary dwelling (except under SB 9 lot split) · Source

  • Parking waived for ADUs within 0.5 miles of transit, in historic districts, or for garage conversions · Source

  • Multifamily buildings may convert 25% of units to ADUs; at least 2 detached ADUs permitted per multifamily lot · Source

  • Cities cannot require owner-occupied primary residence as condition of ADU approval · Source

  • No requirement for ADU to match primary dwelling architecture in most cases · Source

Legislative History

2019 — California AB 68 (2019) · Source

Eliminated owner-occupancy requirement, reduced setbacks to 4 ft, eliminated minimum lot size requirement, streamlined approval to ministerial with 60-day deadline · Source

2019 — California AB 881 (2019) · Source

Prohibited cities from requiring ADU setbacks exceeding 4 ft rear/side, eliminated impact fees for ADUs under 750 sqft, expanded parking waivers · Source

2021 — California SB 9 (2021) · Source

Authorized urban lot splits on single-family parcels, allowing up to 4 units on lots that were previously single-family only. Ministerial approval required for qualifying splits. · Source

2023 — California AB 1033 (2023) · Source

Authorized local jurisdictions to optionally allow ADUs to be sold separately as condominiums from the primary dwelling unit · Source

2024 — California AB 2533 (2024) · Source

Further streamlined ADU permitting, clarified ministerial approval standards, strengthened local compliance requirements · Source

Official Sources

View official law source ↗Read full legal text ↗

What Does Preemption Mean for Local Cities?

Because California law preempts local ordinances, individual cities cannot impose restrictions stricter than the state standard. A city may still have additional administrative requirements, but cannot deny ADU applications that comply with state minimums.

Learn about Californiazoning preemption →

Source: California ADU Law (Government Code Chapter 13, §§66310–66342). Last verified April 3, 2026. View source

Last updated: April 3, 2026
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California ADU Laws (2026) — State Requirements & Local Rules | PropertyZoned