San Diego County ADU & JADU Zoning Bulletin (PDS-PLN-611)

County of San Diego, Planning & Development Services ACCESSORY DWELLING UNIT & JUNIOR ACCESSORY DWELLING UNIT ZONING DIVISION According to California State Law, properties zoned for residential use with an existing or proposed single-family dwelling (SFD) are eligible for the addition of one newly constructed detached Accessory Dwelling Unit (ADU), the conversion of permitted and existing space within either an accessory structure or SFD, and one Junior Accessory Dwelling Unit (JADU). The ADU and JADU must provide complete independent living facilities for one or more persons. Applicants are strongly encouraged to contact the appropriate Fire Department as soon as possible to ensure that their ADU complies with the required fire setbacks and to determine whether fire sprinklers and a fire hydrant are required or not. If your property is located within the County of San Diego, you may be eligible to add at least one ADU and one JADU to your lot with an existing or proposed single-family dwelling (SFD) in a residential or mixed-use zone, provided all the following are met:

• The ADU is either attached to an existing SFD or detached and on the same legal lot. • ADU may be rented but is not intended for sale separate from the primary residence. • Lot does not have a Second Dwelling Unit on the parcel. A conversion of a Second Dwelling Unit into an ADU is potentially permitted and requires approval of a building permit. • The total floor area of an attached ADU shall not exceed 50% of the floor area of the SFD, 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 • The total floor area of a detached ADU shall not exceed 1,200 square feet, independent of the square footage of the existing SFD. • Applicants must provide mathematical computations of the "floor area" for both units on the plot plans, and these calculations must be taken from the interior dimensions of the outside walls. • 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 of the Zoning Ordinance, or unless authorized by an approved Administrative Permit. • Any proposed accessory structure, attached to an ADU, exceeding 1,000 square feet (combined with all other accessory structures per Section 6156.g) and/or more than 12’ in height, are subject to the main building setbacks and height regulations of the Zoning Ordinance. • An attached or detached patio, deck, and/or balcony is subject to Section 4835 of the Zoning Ordinance. • A detached ADU is limited to 25’ in height (except for multifamily complexes). • A minimum setback of at least 4’ from the side and rear lot lines is required for a newly constructed ADU (except any required fire setbacks). If on a corner lot, the exterior side yard setback must be at least 4’ from the edge of easement/street/and/or property line (except any required fire setbacks). Please click here for Zoning Information if your property is within the unincorporated area of the County of San Diego.

If you have any additional zoning questions, please email us at PDSZoningPermitCounter@sdcounty.ca.gov 5510 OVERLAND AVE, SUITE 110, SAN DIEGO, CA 92123 http://www.sdcounty.ca.gov/pds PDS-611 (Rev. 01/7/2026) PAGE 1 of 4

County of San Diego, PDS, Zoning Division ACCESSORY & JUNIOR ACCESSORY DWELLING UNIT Continued • An ADU that is being constructed above a permitted detached accessory structure must also adhere to the setbacks outlined above. The setbacks only apply to the added space above the accessory structure and the ADU can be constructed wholly or partly above the accessory structure, including extending beyond the accessory structure walls. • An ADU that is proposed as attached to an accessory structure must maintain all separations necessary for health and safety purposes. This would include a defined fire and sound separation wall or floor between the ADU and recreation room. Any openings (doors, window, or penetrations) would be required to be fire rated. • An ADU shall provide one parking space. The parking space may be located within the setbacks and in an existing driveway as tandem parking. Parking spaces don’t need to be replaced when a garage, carport, or covered parking structure is demolished in conjunction with the construction of an ADU or converted into an ADU.

• A parking space is only required for a proposed detached ADU in any of the following instances: (1) The proposed new construction of a detached ADU where the SFD is has already been constructed (2) The project site is located more than one-half mile of public transit • The ADU shall not be rented for less than 30 days. • Properties that have multiple (2 or more) existing, non-conforming SFD’s and are in a residential zone that only allows for one SFD, can have an ADU and JADU. • Properties that have an existing non-conforming SFD and are in a zone that does not allow for a SFD, can have an ADU and JADU. Conversions of existing, permitted square footage to an ADU must comply with the following limitations: • No additional development standards such as maximum square footage, height, lot coverage, and setbacks (except for fire safety) are required if an existing and permitted detached or attached accessory structure is being converted into an ADU. Any new addition to the ADU must comply with the setbacks and height regulations outlined on this form.

• An existing and permitted accessory structure could potentially be converted into an ADU. Such a conversion would not be subject to any size requirements. For example, an existing & permitted 3,000 square foot barn could be converted into an ADU without any additional requirements, other than compliance with the fire and building standards for dwelling units. • A portion of the existing and permitted main residence could potentially be converted into an ADU, however, the entire main residence cannot be converted into an ADU. Such a conversion would not be subject to any size requirements as long as a portion remains as the main residence. For example, an entire 4,000 square foot main residence cannot be converted into an ADU, however 2,000 square feet of the main residence can be converted into an ADU while the remaining 2,000 square feet stays as the main residence. • ADU’s converted from accessory structures are eligible for a 150 square-foot expansion solely to accommodate ingress and egress. Any other addition is considered a new construction ADU

and would be subject to the square footage limitations listed for newly constructed ADUs. Please click here for Zoning Information if your property is within the unincorporated area of the County of San Diego. If you have any additional zoning questions, please email us at PDSZoningPermitCounter@sdcounty.ca.gov 5510 OVERLAND AVE, SUITE 110, SAN DIEGO, CA 92123 http://www.sdcounty.ca.gov/pds PDS-611 (Rev. 01/7/2026) PAGE 2 of 4

County of San Diego, PDS, Zoning Division ACCESSORY & JUNIOR ACCESSORY DWELLING UNIT Continued See Junior Accessory Dwelling Units (JADU) requirements below: • One JADU, which shall not exceed 500 square feet, may be permitted on lots with an existing or proposed SFD within a residential or mixed-use zone. • The JADU must be completely contained within an existing or proposed SFD and may include separate sanitation facilities or may share sanitation facilities with the existing structure. • JADU's are not required to have an interior connection to the primary dwelling. However, if the JADU does not include a separate bathroom, the JADU must include an interior entrance to the main living area. • The JADU shall include an efficiency kitchen, which shall include all the following: a. A cooking facility with appliances. b. A food preparation counter and storage cabinets that are of reasonable size in relation to the size of the junior accessory dwelling unit. • When an existing garage, carport, or covered parking space is being demolished in

conjunction with the construction of a JADU or converted into a JADU, the two required parking spaces for the existing SFD need to be replaced. • No additional parking space is required for a JADU. • A JADU must be within an existing or proposed SFD and cannot be attached to an ADU. • JADU’s, and/or additions for JADU’s must comply with main building setbacks, incl. JADU additions for non-conforming SFD’s. Please see Section 6886 of the Zoning Ordinance for setback information on non-conforming SFD’s. • The JADU may be rented, but not for less than 30 days, and is not intended for sale separate from the primary residence. The owner is required to live in one of the two units. • No separate electric meter will be permitted. • JADU’s require that the owner must reside in either the remaining portion of the primary residence or in the newly created JADU. Accessory Dwelling Units less than 800 square feet are subject to the following requirements: • A proposed ADU may encroach into the required front yard setbacks if it is 800 square feet or smaller.

• No parking spaces are required to be provided for this ADU. • Limited to 18’ in height. • If proposed as a conversion of existing space, cannot propose an addition of more than 150 square feet for the sole purpose of ingress and egress. Please click here for Zoning Information if your property is within the unincorporated area of the County of San Diego. If you have any additional zoning questions, please email us at PDSZoningPermitCounter@sdcounty.ca.gov 5510 OVERLAND AVE, SUITE 110, SAN DIEGO, CA 92123 http://www.sdcounty.ca.gov/pds PDS-611 (Rev. 01/7/2026) PAGE 3 of 4

County of San Diego, PDS, Zoning Division ACCESSORY & JUNIOR ACCESSORY DWELLING UNIT Continued Multiple ADU’s may be permitted within portions of an existing or proposed multifamily complex within a residential or mixed-use zone if the following requirements are met. • Only structures/rooms within the existing or proposed multifamily complex that are not used as livable space, including, but not limited to, storage rooms, boiler rooms, passageways, attics, basements, or garages, can potentially be converted at least into one ADU, or multiple ADU’s, up to 25% of the existing multifamily dwelling units. • Detached ADU’s maybe permitted per legal lot that has an existing or proposed multifamily complex if the following requirements are met. a. Up to 2 detached ADUs can be permitted with a proposed multifamily complex. b. If the existing multifamily complex has more than 2 existing units, the number of proposed ADUs can either be equivalent to the number of existing units in the complex up to a maximum of 8 detached ADUs, whichever is less. For example, an existing multifamily

complex with a four-plex (4 units), can potentially propose 4 detached ADUs, not 8. c. Non-conforming multifamily complexes, which are non-conforming due to the zone no longer allowing residential uses, can have either 2 detached ADUs or can potentially convert existing non-habitable space into at least into one ADU, or multiple ADU’s, up to 25% of the existing multifamily dwelling units, not both. d. Detached ADUs within a multifamily complex cannot exceed 18’ in height. e. If the construction of detached ADUs is located within an existing parking lot, replacement parking will not be required, however proposed ADUs must provide 1 parking space for each unit, unless the parcel complies with one of the following: a. Located within one-half mile walking distance of public transit. b. Located within an architecturally and historically significant historic district. c. Part of the proposed or existing primary residence or an accessory structure. d. When on-street parking permits are required but not offered to the occupant of the ADU. e.

When there is a car share vehicle located within one block of the ADU. f. When a permit application for an ADU is submitted with a permit application to create a new single-family dwelling or a new multifamily dwelling on the same lot, provided that the ADU or the parcel satisfies any other criteria listed in Government Code section 66322, subdivision (a)(1)-(5). Any structure designed for human habitation that is divided into two or more independent and attached living units on a single lot is considered a multifamily complex (such as duplex, triplex, stacked dwellings, etc.). Multiple detached single-family dwellings on the same lot are not considered a multifamily complex but may qualify for one ADU and one JADU. For information regarding amnesty for ADUs constructed prior to 2020 per AB 2533, please contact the Zoning Counter. IF YOU HAVE QUESTIONS REGARDING SEPARATE UTILITY CONNECTIONS, SERVICES, OR METERING REQUIREMENTS, PLEASE CONTACT YOUR LOCAL UTILITY AND GUIDANCE PROVIDED THROUGH STATE (ADU Handbook (ca.gov)).

Please click here for Zoning Information if your property is within the unincorporated area of the County of San Diego. If you have any additional zoning questions, please email us at PDSZoningPermitCounter@sdcounty.ca.gov 5510 OVERLAND AVE, SUITE 110, SAN DIEGO, CA 92123 http://www.sdcounty.ca.gov/pds PDS-611 (Rev. 01/7/2026) PAGE 4 of 4