Accessory Structures in Monterey County, CA (2026)
5 county-level rules, plus city-specific rules for 1 city in Monterey County, California.
Verified from official government sources
ADU Rules
Unincorporated Monterey County permits one ADU plus one JADU on lots with a single-family dwelling. Inland (Title 21, section 21.64.030) ADUs may not exceed 1,200 sq ft; JADUs max 500 sq ft. Detached ADUs default to a 16-ft height limit. State ADU law (Gov. Code 65852.2/66310+) preempts local rules where they conflict.
Monterey County Accessory Dwelling Unit (ADU) Rules
Some RestrictionsMonterey County Code § 21.64.030(E)(5), (6), (9), (10)
Side and rear lot line setbacks for ADUs shall be a minimum of four (4) feet and shall also be sufficient for fire and safety... ADUs shall not exceed 1,200 square feet. JADUs shall not exceed 500 square feet. An ADU detached from the principal dwelling shall be subject to the height regulations for a habitable accessory structure or allowed to be up to 16-feet in height, whichever is greater.
ADU Owner Occupancy
In Monterey County's Coastal Zone, an owner who builds a junior accessory dwelling unit must live in either the remaining part of the main house or in the JADU itself, unless the owner is a government agency, land trust or housing organization, per the coastal ADU/JADU zoning regulations.
Monterey County Coastal ADU Owner-Occupancy Rule
Some RestrictionsMonterey County Code § 20.64.030(F)(10)
10.The owner must reside in either the remaining portion of the structure or the newly created JADU, unless the owner is another governmental agency, land trust, or housing organization.
ADU Rental Restrictions
Monterey County's Coastal Zone ADU and JADU regulations bar renting an accessory dwelling unit, junior accessory dwelling unit, or any part of one for 30 consecutive days or fewer; a separate rental is legal only if it runs 31 consecutive days or longer.
Monterey County Coastal ADU 30-Day Rental Floor
Significant RestrictionsMonterey County Code § 20.64.030(D)(2)
An ADU or JADU may be separately rented, provided such rental is for 31 consecutive calendar days or longer. Rental of an ADU, a JADU, or a portion of an ADU or JADU for 30 consecutive calendar days or fewer is prohibited.
Shed & Carport Rules
Small one-story sheds in unincorporated Monterey County (240 sq ft or less, no utilities) generally do not need a building permit, but Planning rules such as zoning setbacks and design control still apply. Larger sheds or any structure with electrical, plumbing or mechanical work require a building permit.
Monterey County Shed and Detached Accessory Structure Rules
Some RestrictionsMonterey County HCD Building & Planning Services FAQ (citing CBC adopted by MCC § 18.02)
A construction permit is not required for a one-story detached structure accessory to detached one and two family dwellings used as tool and storage sheds, playhouses and similar uses, provided the floor area does not exceed 240 square feet and the structure does not contain any electrical, plumbing or mechanical work.
Garage Conversions
Unincorporated Monterey County allows converting an existing garage into an ADU under section 21.64.030. No setback is required for a garage converted (or demolished and rebuilt) as an ADU within the existing footprint, and replacement off-street parking is not required when the garage becomes an ADU.
Monterey County Garage Conversion Rules
Some RestrictionsMonterey County Code § 21.64.030(E)(6)
No setback shall be required for an existing garage that is converted or demolished and reconstructed as an ADU within the existing footprint of the structure. Side and rear lot line setbacks for ADUs shall be a minimum of four (4) feet and shall also be sufficient for fire and safety. A minimum setback of four (4) feet must be maintained from the side and rear lot lines for an ADU that is cons...
Accessory Structures by City in Monterey County
1 cities in Monterey County have their own accessory structures rules. Each link goes to that city's dedicated page with code citations.
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