Accessory Structures in San Luis Obispo County, CA (2026)
5 rules for unincorporated San Luis Obispo County, California.
Verified from official government sources
ADU Rules
Unincorporated San Luis Obispo County permits an accessory dwelling unit (ADU) on any lot with an existing single-family dwelling under Title 22 Section 22.30.470, with a maximum size of 1,200 sq ft, minimum 4 ft side/rear setbacks for detached units, and no off-street parking required.
ADUs allowed countywide; up to 1,200 sq ft, 4 ft setbacks
Some RestrictionsSan Luis Obispo County Code § 22.30.470(F) (Ord. 3409, Jan. 28, 2020)
Maximum size of accessory dwelling. 1,200 square feet, including attics greater than six feet in height, unconditioned storage space, and lofts... Detached accessory dwellings shall comply with the same setback requirements pertaining to distance from property lines or alleys for residential accessory buildings and structures in Section 22.10.140 (Setbacks), however, minimum setback requirement...
ADU Rental Restrictions
San Luis Obispo County lets homeowners rent an accessory dwelling separately from the main house, but only as a long-term tenancy. County Code Sec. 22.30.470.C.4 bars renting all or part of an ADU for less than 30 days, closing off short-term or vacation-rental use of accessory units built under the county's ADU ordinance.
SLO County Bans Short-Term ADU Rentals
Significant RestrictionsSan Luis Obispo County Code Sec. 22.30.470.C.4
4.Rental of accessory dwellings.a.30 days or more. An accessory dwelling may be rented separately from the primary dwelling, but shall not be sold or otherwise conveyed separately from the primary dwelling.b.Less than 30 days. Rental of an entire accessory dwelling or portion of an accessory dwelling for less than 30 days shall be prohibited.c.Exception. Rental of an entire accessory dwelling o...
Shed & Carport Rules
Unincorporated San Luis Obispo County exempts one-story detached residential accessory structures used as tool and storage sheds or playhouses from building permits when the floor area does not exceed 120 sq ft, but they must still meet zoning setbacks: 3 ft from rear/interior side lines and 25 ft from the front property line.
Sheds under 120 sq ft exempt; 3 ft side/rear setback
Some RestrictionsSLO County Planning & Building - Shed (applying CRC permit exemption and Title 22 § 22.10.140)
A one story detached residential accessory structures used as tool and storage sheds, playhouses and similar uses, provided the floor area does not exceed 120 square feet... Typically the setbacks for a 120 square foot shed, that is 12 feet or less in height, are 25 feet from the front property line, or road easement, and 3 feet from the rear and interior side property lines.
Garage Conversions
Unincorporated San Luis Obispo County allows conversion of an existing garage or other accessory structure into an accessory dwelling unit under Title 22 Section 22.30.470(G), with a maximum size of 1,000 sq ft and up to 150 sq ft of expansion permitted for ingress and egress.
Garage to ADU conversion allowed; up to 1,000 sq ft
Some RestrictionsSan Luis Obispo County Code § 22.30.470(G) (Ord. 3409, Jan. 28, 2020)
The accessory dwelling or junior accessory dwelling will be completely within the (1) proposed space of a single-family dwelling, (2) existing space of a single-family dwelling, or (3) existing space of an accessory structure. The existing accessory structure to be converted to an accessory dwelling may be expanded by a maximum of 150 square feet. Such expansion shall only be permitted to accom...
Tiny Homes
San Luis Obispo County adopted California Residential Code Appendix BB so a tiny house can be permitted as a single dwelling unit. Section 19.03.020(2) amends Appendix BB Section 101.1's scope so the appendix applies only to tiny houses built as dwellings, not to park models or other recreational vehicles used as housing.
SLO County Adopts Tiny House Building Code
Some RestrictionsSan Luis Obispo County Code § 19.03.020(2) (adopting CRC Appendix BB § 101.1)
Adopt Appendix BB - TINY HOUSES Amend Appendix BB Section 101.1 to read as follows: Scope. This appendix shall be applicable to tiny houses used as single dwelling units. Tiny houses shall comply with this code except as otherwise stated in this appendix. These provisions do not allow for park models or other recreation vehicles to be considered a habitable dwelling unit.
All San Luis Obispo County ordinances
See every category we cover for San Luis Obispo County: parking, noise, fences, fires, animals, pools, and more.
San Luis Obispo County Ordinance Hub →