California ADU rules · Monterey County
Can I Build an ADU in Marina?
Yes — you can build an ADU in Marina. California's statewide ADU law requires every city, including Marina, to approve a qualifying accessory dwelling unit by right, plus a junior ADU (JADU) on a single-family lot. What varies city to city are the local specifics below.
Can you build one?
ADUs allowed
CA state lawYes — by right
ADUs and JADUs are allowed by right in all residential and mixed-use zones; ministerial approval, no hearing.
Units on a single-family lot
CA state law1 ADU + 1 JADU
At least one ADU and one JADU per single-family lot (a conversion ADU may also be possible).
Units on a multifamily lot
CA state lawConversion ADUs (≥1, up to 25% of units) + up to 8 detached
Conversions of non-livable space (at least 1, or up to 25% of existing units) plus up to 8 detached ADUs on a lot with existing multifamily — never exceeding the number of existing units. JADUs are single-family only.
Junior ADU (JADU)
CA state lawAllowed
Up to 500 sq ft, within the walls of an existing single-family home (single-family lots only).
Size & height
Max detached ADU size
CA state law1,200 sq ft
Statewide default cap for detached new-construction ADUs in the absence of a compliant local ADU ordinance. The unconditional by-right floor a city must always allow is 800 sq ft (see Guaranteed minimum size); a city with a compliant ordinance may set its own ceiling.
Max attached ADU size
CA state law50% of the primary dwelling, but ≥850 sq ft (≥1,000 sq ft for 2+ bedrooms) is always allowed
Guaranteed minimum size
CA state law800 sq ft
An 800 sq ft ADU must be allowed regardless of FAR/lot-coverage caps; a city also cannot cap an attached ADU below 850 sq ft (1,000 for 2+ bedrooms).
Max JADU size
CA state law500 sq ft
Max height
Local rule24 ft
Marina is MORE permissive than the 16-ft state baseline in one case: an ADU may be up to 24 ft when constructed on a vacant lot together with a newly built primary single-family dwelling, provided the ADU's first story includes parking for the unit with unobstructed driveway/alley access at least 12 ft wide. Otherwise a detached ADU is limited to 16 ft (state transit/two-story 18-ft and multifamily 20-ft allowances still apply).
Setbacks
Side setback
Local rule4 ft
4-ft minimum side and rear setback for an ADU 24 ft or less in height (matching the state cap); front and street-side setbacks follow the underlying zone. An ADU over 24 ft must meet the main structure's setbacks. A recorded constraint (e.g., a public-utility easement) prevails where applicable.
Front setback
CA state lawNo front setback may block the mandatory 800 sq ft / 16-ft / 4-ft-setback ADU; otherwise per base zone
Separation from main house
CA state lawNone required
No statewide separation requirement between the ADU and the primary dwelling.
Parking
Parking required
CA state lawUp to 1 space
At most 1 space per ADU (or per bedroom, whichever is less) — and waived in the common cases below.
Transit parking exemption
CA state lawYes — no parking required near transit & for conversions
No parking may be required within ½ mi walking distance of transit, in a historic district, for an ADU within an existing structure, within one block of car-share, or in certain permit-parking areas.
Garage-conversion replacement parking
CA state lawNot required
When a garage/carport is demolished or converted to build an ADU, replacement parking cannot be required.
Approval, timeline & cost
Approval path
CA state lawMinisterial (by right)
No public hearing or discretionary design review for a qualifying ADU.
Approval timeline
CA state law60 days
The agency must act within 60 days of a complete application — and the ADU is deemed approved if it does not.
Owner-occupancy
CA state lawOnly for a JADU
No owner-occupancy requirement for ADUs (the prior sunset was removed). A JADU may require owner-occupancy, principally where it shares sanitation with the main house.
Impact-fee waiver
CA state lawWaived under 750 sq ft
An ADU of 750 sq ft or less pays no impact fees (the 750 sq ft threshold itself is exempt under § 66311.5); larger ADUs pay fees proportional to the primary dwelling. JADUs (≤ 500 sq ft) are exempt.
Permits required
CA state lawBuilding permit
Only a ministerial building permit — no conditional use permit or discretionary design review for a qualifying ADU.
Marina-specific factors that can change the answer
State law sets the floor, but these local conditions often decide whether a specific parcel works.
Recorded ADU deed restriction
Before a building permit issues, Marina requires the owner to record a declaration of restrictions stating the ADU may not be sold separately from the primary dwelling and prohibiting rentals shorter than 30 days (MMC § 17.42.040; consistent with state law). This is a recording step, not an added eligibility standard.
Marina adopted a local ADU ordinance — MMC § 17.42.040 (Ord. 2021-05, October 2021) — that mostly follows California state ADU law (4-ft side/rear setbacks, ministerial by-right approval, JADU ≤500 sq ft, no added parking for most parcels because they sit within ½ mile of transit). Its distinctive local rule is actually more generous on height: an ADU can reach 24 ft when built on a vacant lot alongside a new primary single-family home, if its first story provides parking with ≥12-ft driveway/alley access. Marina also requires a recorded deed restriction (no separate sale, 30-day-minimum rental) before permit issuance. Confirm the deed-restriction form with Marina Planning.
Frequently asked questions
Can I build an ADU in Marina?
Yes. California's statewide ADU law requires Marina to approve a qualifying accessory dwelling unit ministerial (by right), plus a junior ADU (JADU) on a single-family lot.
How big can an ADU be in Marina?
A detached ADU of at least 1,200 sq ft must be allowed, and an ADU of 800 sq ft can never be zoned out by floor-area or lot-coverage limits. A JADU can be up to 500 sq ft.
What are the setback requirements for an ADU in Marina?
Side and rear setbacks are limited to 4 ft. No front setback may block the mandatory 800 sq ft / 16-ft / 4-ft-setback ADU; otherwise per base zone.
Is parking required for an ADU in Marina?
Up to 1 space. No parking can be required within ½ mile of transit, for conversions, or for units inside the primary home. When a garage is converted, replacement parking is not required.
How long does ADU approval take in Marina?
A complete application must be acted on within 60 days, with ministerial (by right) — no public hearing or discretionary design review for a qualifying ADU.
Do I have to live on the property to build an ADU in Marina?
Owner-occupancy: only for a jadu. ADUs under 750 sq ft are also exempt from impact fees.
Sources
- Marina Mun. Code § 17.42.040 (Accessory Dwelling Units; Ord. 2021-05)
- MMC § 17.42.040.A.3.d.i (Ord. 2021-05)
- MMC § 17.42.040.A.3.f.iii (Ord. 2021-05)
- Cal. Gov. Code §§ 66310–66342 (ADU Law)
- HCD 2025 Accessory Dwelling Unit Handbook
- Cal. Gov. Code § 66317 (ministerial approval, 60-day deadline)
- Cal. Gov. Code § 66323 (by-right ADU/JADU, 800 sq ft, 4-ft setbacks)
- Cal. Gov. Code § 66333 (junior ADUs)
- Cal. Gov. Code § 66321 (size minimums & height)
- Cal. Gov. Code § 66322 (ADU parking; § 66334 covers JADU parking)
- Cal. Gov. Code § 66314 (local ordinance standards)
- Cal. Gov. Code § 66315 (owner-occupancy)
- Cal. Gov. Code § 66311.5 (impact fees: none for an ADU ≤ 750 sq ft or JADU ≤ 500 sq ft)
Last updated 2026-06-28. This is an AI-assisted summary of Marina's ADU rules, drawn from its published ordinance and California ADU law — general information, not legal advice, and it may be incomplete or out of date. Verify the controlling rule for your specific parcel with Marina Planning before relying on it.
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