Data report · 2026

State of California ADU Rules 2026

California's ADU law sets a statewide floor, but what you can actually build is decided city by city. Across the 487 California cities in GoCodebook's ADU dataset,405 have at least one recorded local rule for the five fields below, and 450 carry ordinance-cited local data. Every number on this page is computed directly from the dataset behind ourcity-by-city comparison.

Where the dataset records local rules

331

cities with a local rule on detached adu maximum size

State baseline: 1,200 sq ft

cities with a local rule on side & rear setbacks

State baseline: 4 ft

288

cities with a local rule on required parking

State baseline: Up to 1 space

246

cities with a local rule on owner-occupancy

State baseline: Only for a JADU

cities with a local rule on approval timeline

State baseline: 60 days

Recorded local size limits above the state default

The 1,200 sq ft default maximum applies where there is no compliant local ADU ordinance. It is not a guaranteed size on every lot. The recorded local limits below exceed that default. Check each city's conditions and source before using a listed limit. See the HCD ADU Handbook, size requirements.

City	Detached ADU max size
Hidden Hills	1,500 sq ft
Menifee	1,500 sq ft
Woodside	1,500 sq ft
Beverly Hills	1,400 sq ft
Fresno	1,400 sq ft

About this data

The dataset pairs the California state-law baseline with each city's local ADU ordinance where one has been compiled and cited (see our methodology). A local-rule count records the source of a value, not whether it is more permissive than state law. A local value can equal the state baseline. Fields without a local override use the state baseline. Explore the full table on ADU rules by city, read California ADU law explained, or open any city's page for its rules with citations.

Journalists and researchers: you're welcome to cite these figures with attribution to GoCodebook (link to this page). Figures are AI-compiled from adopted ordinances and cited to the ordinance text — spot-check the cited section before publication. Figures regenerate as the underlying ordinance data is updated — this page always reflects the current dataset.

Check the rules for your exact parcel

Aggregate stats can't see your lot. Ask GoCodebook about your address for the ADU size, setbacks, parking and permit path that actually apply — with citations.

Check my parcel free