San Luis Obispo County, CA Accessory Structures: ADU Rental Restrictions (2026)

Accessory dwellings in unincorporated San Luis Obispo County are authorized under California Government Code Sections 66310-66342 and receive ministerial Zoning Clearance review under Sec. D, without discretionary hearings. Subsection C, "Limitations on use," keeps the rental side of that authorization narrow. Sec. a confirms an accessory dwelling can be rented out on its own, separately from the primary residence, as long as the tenancy runs 30 days or more; the unit still cannot be sold or conveyed apart from the primary dwelling. Sec. b then flips that permission around for shorter stays: renting all or any part of an accessory dwelling for less than 30 days "shall be prohibited," which rules out nightly or weekly vacation-rental use of a county-permitted ADU or junior ADU.

A narrow grandfather clause survives in Sec. c: a short-term rental use approved before February 28, 2020 may continue, but no new sub-30-day rental use can be established. The restriction sits alongside other C-subsection limits, including the rule that an ADU cannot receive a certificate of occupancy before the primary dwelling does, and that ADUs built under this Section do not count toward the parcel's allowed residential density. Owners wanting a short-term or vacation rental instead need the county's separate Residential Vacation Rental standards in Sec. 510, which govern the primary dwelling, not accessory units built under this Section.