San Clemente, CA Accessory Structures: ADU Rules (2026)
ADU rules in San Clemente, CA, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.
Key Facts
- Detached ADU height
- 16 feet; 18 feet near transit or on multi-story multi-family lots
- Maximum ADU size
- 850 sq ft studio or one bedroom; 1,000 sq ft for two or more
- Maximum JADU size
- 500 square feet of interior livable space
- Side and rear setback
- Four feet minimum, unless the district is less restrictive
- Parking
- One space per ADU, with seven listed exemptions
- Impact fees
- None for ADUs under 750 square feet
- Rental limit
- No rentals of 30 days or less
Summary
San Clemente Municipal Code § 17.28.270 approves accessory dwelling units in residential and mixed-use zones with a building permit and no minimum lot area. Detached units top out at 16 feet in the base case, new attached or detached units cap at 850 square feet for a studio or one bedroom and 1,000 square feet for two or more bedrooms, and side and rear setbacks start at four feet.
There shall be no minimum lot area required to establish an accessory dwelling unit and/or junior accessory dwelling unit. ... Attached and detached accessory dwelling units shall provide a minimum setback of four feet from all side property lines and rear property lines not abutting an alley unless the setback requirements of the underlying zoning district are less restrictive. ... Detached accessory dwelling units shall not exceed a height of 16 feet except as noted below: ... The maximum size of a detached or attached accessory dwelling unit shall be 850 square feet of interior livable space for a studio or one bedroom unit and 1,000 square feet of interior livable space for a two or more bedroom unit. ... One parking space shall be required for each accessory dwelling unit. ... No impact fee or connection fee is required for an ADU that provides less than 750 square feet of interior livable space;
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Traffic: Supplement 30 | Code of Ordinances: Supplement 66 Update 1).
Full Breakdown
Section 17.28.270 carries out California Government Code Sections 66310-66342 for accessory dwelling units (ADUs) and junior accessory dwelling units (JADUs). Units are approved in any residential or mixed-use zoning district, and in commercial districts where residential development is authorized under the Housing Overlay or State law, subject to a building permit and an existing or proposed dwelling on the lot. A conforming unit is not counted against density or any growth-limiting program.
Counts per lot: a single-family lot is allowed one attached ADU, one detached new-construction ADU, one detached conversion of an accessory structure, and one JADU. On a lot with an existing multi-family dwelling, up to eight detached ADUs are allowed, capped at the number of existing units; a proposed multi-family dwelling gets two detached ADUs. Converting non-livable space such as storage rooms, attics, basements or garages inside an existing multi-family building yields at least one and up to 25 percent of the existing units. A JADU is not permitted on a multi-family lot.
Setbacks: ADUs follow the zoning district, except that attached and detached units need a minimum four feet from side lot lines and from rear lines not abutting an alley, unless the district is less restrictive. Front setbacks of the district apply unless they would physically preclude a qualifying ADU. Conversions and same-footprint replacements keep their existing setback, and a garage replacement needs the building and demolition permits issued concurrently.
Height: internal and attached units follow the district limit. Detached units stop at 16 feet, 18 feet on a lot with a multi-family, multi-story dwelling or within one-half mile walking distance of a major transit stop or high-quality transit corridor, plus two feet to match the primary unit's roof pitch. A unit above a detached garage is held to two stories and the district height.
Size: 850 square feet for a studio or one bedroom, 1,000 for two or more bedrooms, and 500 for a JADU. Conversions are exempt from the size caps, and no setback, floor area, open space or site coverage rule can shrink a unit below 800 square feet when there is no alternative.
Violations & Fines
Renting an ADU or JADU for 30 days or less violates § 17.28.270(G)(2), and selling one apart from the lot and principal dwelling violates (G)(1) except as Government Code section 66341 allows. A JADU needs a deed restriction recorded and filed with the Planning Division before its building permit issues. For a breach of that restriction, the City is authorized to seek any remedy at law or equity, including an injunction against use of the JADU or abatement of the illegal unit. No ADU certificate of occupancy issues before the primary dwelling's, with a narrow wildfire-disaster exception for detached units.
Frequently Asked Questions
How many ADUs can I build on my San Clemente lot?
Do I need to add parking for a San Clemente ADU?
Are impact fees charged on a San Clemente ADU?
Can I rent my ADU short term or sell it separately?
Can San Clemente deny a permit for an unpermitted ADU built before 2020?
Sources & Official References
Other rules in San Clemente
California rules heatmap·Compare San Clemente to another location·View the California accessory structures overview
See something wrong?
Help us keep this page accurate. If you notice an error or outdated information, let us know.
ADU Rules in Nearby Cities
How other cities in Orange County handle adu rules.