San Diego County, CA Accessory Structures: ADU Rental Restrictions (2026)
Key Facts
- Minimum rental term
- 31 days
- Applies to
- ADUs and JADUs
- Governing section
- Zoning Ord. § 6156.x.A.3
- Scope
- Unincorporated county only
Summary
Unincorporated San Diego County bars renting an accessory dwelling unit for stays under 31 days, blocking short-term rental use of ADUs.
ADU may be rented but is not intended for sale separate from the primary residence, unless the lot is subdivided in conformance with qualifications for the ministerial approval of a two-lot subdivision creating a separate lot for each dwelling, or condominiums are created in conformance with requirements outlined under Section 6156.x.D. of the County’s Zoning Ordinance pertaining to the sale of ADUs, or the conditions pertaining to Nonprofits and tenancy in common agreements established under Section 66341 of the California Government Code are met.
3. The ADU shall not be rented for a term of less than 31 days.
4. The total floor area of an attached ADU shall not exceed 50% of the floor area of the primary residence, up to a maximum floor area of 1,200 square feet. The 50% square foot limitation is not applicable for attached ADUs up to 850 square feet or up to 1,000 square feet if it has more than one bedroom.
5. The total floor area of a detached ADU shall not exceed 1,200 square feet, independent of the square footage of the existing primary residence.
6. Applicants must provide mathematical computations of the "floor area" for both units on the plot plans, and these calculations must be taken from the exterior dimensions of the outside walls.
7. Total floor area of a proposed accessory structure attached to a detached ADU shall not exceed the allowable combined square footages per Section 6156.g
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: 2026 S-141: Administrative: Current through Ord. No. 11007 (N.S.), effective 7-10-26 | Regulatory: Current through Ord. No. 11008 (N.S.), effective 7-24-26).
Full Breakdown
Under Section 6156.x.A.3 of the county Zoning Ordinance, an ADU built in the unincorporated area "shall not be rented for a term of less than 31 days." That kills nightly or weekly rentals through platforms like Airbnb: an ADU can only be leased as a longer-term residence, whether occupied by the property owner, a family member, or a tenant. The rule sits inside the county's broader ADU permit-approval criteria (Section 6156.x.A), alongside size, setback, height, and parking standards that apply when an ADU or JADU is approved on a residential or agricultural lot.
Violations & Fines
Renting an ADU for a term under 31 days violates the zoning approval conditions; Code Compliance can pursue it as a zoning violation, and repeated short-term rental use can jeopardize the ADU's permit standing.
Frequently Asked Questions
Can I list my county ADU on Airbnb for a weekend?
Does the 31-day rule apply inside the City of San Diego?
Sources & Official References
Other rules in San Diego County
California rules heatmap·Compare San Diego County to another location·View the California accessory structures overview
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