City · California
ADU rules in Costa Mesa
These are the primary sources for accessory dwelling unit regulations in Costa Mesa: the city'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.
ADU regulations
- costamesaca.govOfficial sourceVerified July 2026https://www.costamesaca.gov/government/departments-and-divisions/economic-and-development-services/planning/accessory-dwelling-units-adu
- costamesaca.govOfficial sourceVerified July 2026https://www.costamesaca.gov/home/showdocument?id=48904
- costamesaca.govOfficial sourceVerified July 2026https://www.costamesaca.gov/home/showdocument?id=48902
Short-term rental rules
Planning to rent your ADU on Airbnb or VRBO? Costa Mesa regulates short-term rentals separately; check these before counting on nightly rental income.
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See California statewide rulesSpotted something outdated?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 Costa Mesa has updated its ordinance, report it and we'll verify against the official source.
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