San Benito County, CA Accessory Structures: ADU Rules (2026)
ADU rules in San Benito County, CA, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.
Key Facts
- Review type
- Ministerial, not discretionary
- Permit needed
- Building permit only
- Decision deadline
- 60 calendar days
- Extra planning permit
- None required
Summary
Detached and attached ADUs in unincorporated San Benito County need only a ministerial building permit, no discretionary planning approval, and the county must issue it within 60 days of a complete application.
Ministerial action. Approval or denial of an accessory dwelling unit or junior accessory dwelling unit is a ministerial action and subject to compliance with the standards in this section and all other applicable codes.
(2) Building permit. All accessory dwelling unit or junior accessory dwelling units shall require a building permit, subject to all the standard application and processing fees and procedures that apply to building permits generally. No other planning-related permit is required.
(3) Issuance of permit. The County shall issue a building permit within 60 calendar days from the date on which the County received a completed application, unless either.
(a) The applicant requests a delay, in which case the 60-day time period is put on hold for the period of the requested delay; or
(b) The application to create an accessory dwelling unit or junior accessory dwelling unit is submitted with an application to create a new single-family dwelling unit on the parcel. The County may delay acting on the accessory dwelling unit application until such time as the new single family dwelling unit is approved.
(E) ADU terms and definitions. The following terms are used in this section. For definitions, see the Glossary in
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: 2025 S-28: current through Ordinance 1078).
Full Breakdown
In unincorporated San Benito County, approving an accessory dwelling unit or junior ADU is a ministerial action, not a discretionary permit: staff cannot deny a compliant application based on design review or neighbor input. Applicants need only a standard building permit, paying the usual building-permit fees, with no separate planning entitlement required. The county must issue the building permit within 60 calendar days of receiving a completed application, unless the applicant requests a delay or bundles the ADU application with a new single-family home application, which the county may hold until the primary home is approved.
Violations & Fines
There's no separate violation for the permit process itself: build without the required building permit and the structure is subject to San Benito County's standard building-code and code-enforcement penalties under Titles 1 and 21.
Frequently Asked Questions
Does an ADU in unincorporated San Benito County need a use permit?
How long does the county have to approve an ADU permit?
Sources & Official References
Other rules in San Benito County
How San Benito County compares: Easiest Cities to Build an ADU·California rules heatmap·Compare San Benito County to another location·View the California accessory structures overview
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