County · California
ADU rules in San Bernardino County
These are the primary sources for accessory dwelling unit regulations in San Bernardino County: the county's own zoning code, planning department pages, and permit guides. Start here before talking to anyone: the rules below are what your permit reviewer will apply.
Unincorporated areas only
County zoning applies only outside city limits. If your property is inside a city or town, that municipality's own ADU ordinance governs instead, even though it sits within San Bernardino County.
Find your city's rules in CaliforniaADU regulations
- lus.sbcounty.govOfficial sourceVerified July 2026https://lus.sbcounty.gov/wp-content/uploads/sites/48/LUS-ADU-Handout-3.20.2026.pdf
- codelibrary.amlegal.comOfficial sourceReviewed July 2026https://codelibrary.amlegal.com/codes/sanbernardino/latest/sanberncty_ca/0-0-0-170733Browse the full code library
California statewide law also applies
California sets baseline ADU rights at the state level. Where local rules are stricter than state law allows, state law usually wins, so both are worth reading.
See California statewide rulesSpotted something outdated?
Zoning codes change. If a link is dead or San Bernardino County has updated its ordinance, report it and we'll verify against the official source.
Report a correctionReady to build?
Planning an ADU in San Bernardino County?
Tell us about your project and we'll match you with vetted local designers and builders as we bring them online. No cost, no obligation.