Research by DoINeedAPermit Research Team · Updated May 2026
The Short Answer
Permits are mandatory for all ADU types in Marina. California state law (Gov. Code 65852.2 and AB 881) allows you to build ADUs even where local zoning previously prohibited them — but you still need a building permit and must follow Marina's specific design, parking, and utility rules.
Marina is a small coastal city in Monterey County with tight land constraints and a historically restrictive local zoning code that used to ban ADUs outright. Starting in 2017, California state ADU law changed that: Marina cannot deny you a permit for a qualifying ADU purely on zoning grounds. However, Marina's building department still enforces its own local standards on lot size, setbacks, parking (often waived for ADUs under 750 sq ft), utility infrastructure, and design review in the downtown historic district. The city operates under a 60-day review clock per AB 671 (state law), but Marina's actual processing time for ADUs runs 8–12 weeks because the city requires full plan review, including planning staff sign-off on state-law compliance. Marina's permit portal is city-managed; you can file online or in person at City Hall. The city has no explicit pre-approved ADU plan library, so custom drawings or standardized third-party ADU plans (common in coastal CA) usually require full structural and MEP review. This is different from, say, Monterey or Pacific Grove, which have adopted fast-track ADU processing and waived parking for junior ADUs — Marina has not yet codified those exemptions. Detached ADUs on small lots (under 6,000 sq ft) often hit setback pushback; garage conversions usually sail through if the existing structure is sound and utilities can be served.

What happens if you skip the permit (and you needed one)

Marina ADU permits — the key details

California Government Code 65852.2 (amended by AB 881, effective Jan 1, 2020) strips away Marina's old zoning prohibition on ADUs. The state law says the city cannot deny you a permit for a qualifying ADU — meaning a residential unit of no more than 1,200 sq ft (or 65% of primary dwelling, whichever is smaller) — on zoning grounds alone. A junior ADU (interior conversion sharing utilities, ≤500 sq ft, ≤75% of primary dwelling floor area) has even lighter restrictions. However, Marina's Building Department still enforces setback, lot-size, parking, utility, and design standards. The city's local code does not explicitly waive parking for ADUs under 750 sq ft (as some CA cities do), so you may face parking-variance requirements on tight lots. The city is also subject to the 60-day AB 671 shot clock for ministerial ADU applications (those that clearly comply with state law and local standards); however, Marina interprets most ADU projects as requiring discretionary planning review, which extends the timeline to 8–12 weeks. This gray area — ministerial vs. discretionary — is common in coastal CA cities and often causes delays. Detached ADUs must comply with IRC R401-R408 (foundation, frost depth does not apply in Marina's coastal zone but drainage and expansive-soil protocols do), IRC R310 (two independent egress routes if bedroom count ≥2), and NEC 210 (separate electrical service and sub-metering). Garage conversions are faster because the structure exists, but the city requires proof the primary residence has adequate parking (2 spaces minimum); if on-street or easement parking is your only option, the ADU may be denied or require a variance.

Every project is different.

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City of Marina Building Department
Contact city hall, Marina, CA
Phone: Search 'Marina CA building permit phone' to confirm
Typical: Mon-Fri 8 AM - 5 PM (verify locally)
Disclaimer: This guide is based on research conducted in May 2026 using publicly available sources. Always verify current accessory dwelling unit (adu) permit requirements with the City of Marina Building Department before starting your project.