California ADU rules · Monterey County
Can I Build an ADU in Carmel-by-the-Sea?
Yes — you can build an ADU in Carmel-by-the-Sea. California's statewide ADU law requires every city, including Carmel-by-the-Sea, 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
CA state law16 ft
16 ft baseline; cities must allow 18 ft within ½ mi of a major transit stop or where the primary dwelling is two-story, and 20 ft on a lot with a multistory multifamily building.
Setbacks
Side setback
CA state law4 ft
A city cannot require more than 4 ft side or rear setback; conversions of existing structures are exempt.
Rear setback
CA state law4 ft
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
Local ruleMinisterial (by right)
A conforming ADU is approved ministerially with no hearing — and, because Carmel lies entirely within the Coastal Zone, the City processes the required coastal development permit ministerially without a public hearing as well.
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.
Carmel-by-the-Sea-specific factors that can change the answer
State law sets the floor, but these local conditions often decide whether a specific parcel works.
Coastal Zone (entire city) — coastal development permit
All of Carmel-by-the-Sea is within the California Coastal Zone. A coastal development permit is required for an ADU, but CMC § 17.08.050(G) directs the City to act on it ministerially without a public hearing; Coastal Act / Local Coastal Program resource protections still apply.
On-the-books ordinance conflicts with current state law (preempted)
Carmel's adopted ADU text (Ord. 2019-03/2023-06) predates the 2024 recodification and contains standards now below the state floor — a 600 sq ft detached cap, a 12-ft detached height limit, a required owner-occupancy covenant, and a 120-day review period. HCD notified the City on 2025-10-08 that these conflict with State ADU Law. State minimums control: an 800 sq ft / 16-ft ADU must be allowed, no owner-occupancy may be required for an ADU, and the agency must act within 60 days. Confirm the City is applying the state floor, not the stale local numbers.
Historic resources
Carmel has an extensive inventory of historic properties and a strong design-review culture; an ADU on or near a listed resource still triggers historic review. State law bars requiring replacement parking for a garage-conversion ADU even in a historic context.
Carmel-by-the-Sea adopted its ADU rules in CMC § 17.08.050(G) (Ord. 2019-03, amended Ord. 2023-06), but that text predates California's 2024 ADU recodification and HCD wrote to the City on 2025-10-08 flagging it as out of compliance — its 600 sq ft detached cap, 12-ft detached height limit, owner-occupancy covenant, and 120-day timeline are all below the controlling state floor and are preempted. Until Carmel re-adopts, the enforceable rules are the state minimums (≥800 sq ft, 16 ft, no owner-occupancy, 60-day ministerial review). The one durable local fact: because the whole city is in the Coastal Zone, the required coastal development permit is processed ministerially without a hearing. Verify current standards and historic-review triggers with Carmel Community Planning & Building.
Frequently asked questions
Can I build an ADU in Carmel-by-the-Sea?
Yes. California's statewide ADU law requires Carmel-by-the-Sea 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 Carmel-by-the-Sea?
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 Carmel-by-the-Sea?
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 Carmel-by-the-Sea?
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 Carmel-by-the-Sea?
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 Carmel-by-the-Sea?
Owner-occupancy: only for a jadu. ADUs under 750 sq ft are also exempt from impact fees.
Sources
- Carmel-by-the-Sea Mun. Code § 17.08.050(G) (Ord. 2019-03; amended Ord. 2023-06)
- CMC § 17.08.050(G) (ministerial ADU permit + ministerial coastal development permit)
- CMC § 17.08.050(G) (coastal development permit)
- HCD ADU ordinance technical-assistance letter to Carmel-by-the-Sea (2025-10-08)
- CMC § 17.08.050(G)
- 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 Carmel-by-the-Sea'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 Carmel-by-the-Sea Planning before relying on it.
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