Accessory Structures in San Diego County, CA (2026)

San Diego County Zoning Ordinance § 6156.x

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 o...

San Diego County Zoning Ordinance § 6156.x.A.25

A homeowner applying for a permit for a previously unpermitted ADU or JADU constructed before January 1, 2020, shall not be required to pay impact fees or connection or capacity charges except when utility infrastructure is required to comply with all applicable Health and Safety Code requirements. Necessary permits to correct noncompliance with health and safety standards shall be approved wit...

San Diego County Zoning Ordinance § 6156.x(B)(3)(a)(iii)

The JADU shall be considered legal only so long as either the primary residence, or the ADU, is occupied by the owner of record of the property, except when the home is owned by an agency such as a land trust or housing organization in an effort to create affordable housing;  iv.   The restrictions shall be binding upon any successor in ownership of the property and lack of compliance with this...

San Diego County Zoning Ordinance § 6156.x.A.3

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...

San Diego County Zoning Ordinance § 4842(a)

SETBACKS FOR DETACHED ACCESSORY BUILDINGS AND STRUCTURES. a. No detached accessory building shall be located with walls closer than 3 feet or eaves closer than 2 feet from interior side or rear property lines. b. No detached accessory building authorized by Section 6156.g exceeding 1,000 square feet in area shall be located within a required setback pursuant to Section 4810.

San Diego County Zoning Ordinance § 6156.x(A)(11), (A)(13)

An existing and permitted accessory structure may be converted into an ADU. Such a conversion is not subject to any size requirements if it does not expand beyond the existing envelope of the permitted accessory structure. 12.   An ADU may be attached to an existing and permitted, or proposed recreation room, if there is a defined fire and sound separation wall or floor between the ADU and recr...

San Diego County Code § 92.2.RAPPBB

SEC. 92.2.RAPPBB. APPENDIX BB. Appendix BB of the California Residential Code is adopted in its entirety as part of the County Residential Code. APPENDIX BB TINY HOUSES RAPPBB 101.1 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.