Accessory Dwelling Units (ADUs)


 ADU Ordinance (12.18.23)

Following adoption, the City must submit the Ordinance to the California Department of Housing and Community Development (HCD) within 60 days for review in accordance with Government Code Section 65852.2(h); and must submit the Ordinance/Local Coastal Program Amendment to the California Coastal Commission for certification in accordance with the California Coastal Act in order for the Ordinance to take effect. The status of these state level reviews will be reported out to the City Council in February 2024.

What is an ADU? What is a JrADU?

As set forth in California Government Code section 65852.2, an Accessory Dwelling Unit (ADU) is a smaller (detached or attached) secondary dwelling unit with complete, independent living facilities (kitchen, bathroom, and access) that is located on the same parcel as a primary dwelling unit (existing or proposed). The ADU can be located within or attached to a single dwelling unit, within a multiple dwelling unit building, or in a separate detached structure.

As set forth in California Government Code section 65852.22, a Junior ADU (JrADU) is a small dwelling unit (500 square feet maximum in size) that is developed within the walls of a single dwelling unit (existing or proposed). The JrADU must have a separate entrance, efficiency kitchen, and access to a bathroom either within the JrADU or via shared access with the primary dwelling unit.  A JrADU is allowed only within the single dwelling unit and is not permitted within an accessory structure or multiple dwelling unit development. JrADUs are only allowed on lots in single dwelling unit zones.

New State Law Changes in Effect

On January 1, 2020, a new package of California laws related to ADUs took effect.  Visit the staff report (Item 9: California Housing Legislation Update and Confirmation of the Process for Update to the Local Accessory Dwelling Unit Regulations) for the January 13, 2020 City Council meeting to understand how the change in State law relates to the City of Del Mar.  The most significant changes amended Government Code sections 65852.2 and 65852.22.

Applicable ADU Regulations and State Guidance

All previously adopted City Ordinances related to ADUs are null and void, including Ordinance 966. Per State law, when a local agency has not adopted an ordinance consistent with California Government Code Section 65852.2 and/or 65852.22 and receives an application for a permit to create an ADU or JrADU, the local agency shall approve or disapprove the application ministerially without discretionary review in accordance with Section 65852.2 and/or 65852.22.  This requires “harmonizing“ between State ADU law and the Coastal Act as necessary to protect coastal access and coastal resources. For example, where necessary to protect coastal access and coastal resources, the City has the ability to scale back and/or modify the placement and size of the proposed ADU. This is because the Coastal Act is not superseded and the Government Code specifically states that it is not intended to “in any alter or lessen the effect or application of the California Coastal Act of 1976”.  Submitted applications for ADUs will be processed in accordance with the City’s procedures for approval of administrative Coastal Development Permits per Del Mar Municipal Code (DMMC) Section 30.75.080.

The State’s ADU regulations are complex.  Guidance is provided by the California Department of Housing and Community Development (HCD) in the 2022 HCD ADU Handbook and the California Coastal Commission January 21, 2022 letter titled “Updates Regarding the Implementation of New ADU Laws” that was addressed to the Planning Directors of Coastal Cities and Counties. Some elements in the State’s ADU regulations and guidance are contradictory. For example, the Government Code provides different ADU standards for “single family” and “multifamily”, but does not provide a definition of what constitutes “multifamily”. 

Consistent with local definitions, single dwelling unit lots with a maximum of one primary dwelling unit have a right to a maximum of one ADU and one JrADU per lot.  Lots with multiple existing primary dwelling units (e.g. attached or unattached duplex) are allowed to have more than one ADU per lot in accordance with California Government Code Section 65852.2(e)(1)(C) and (D).  This is consistent with the City’s definition of “multiple dwelling unit” per DMMC Section 30.04.130(F), which applies to a building or lot containing two or more dwelling units.  This includes lots with multiple units located within a common building or that share a common wall and to lots with multiple detached units that do not share a common wall.  Lots with existing multiple dwelling unit development have a right to two “detached” ADUs on the lot per Government Code Section 65852.2.  However, to protect coastal access and coastal resources and harmonize with the Coastal Act, the City can use the applicable Coastal Development Permit findings for approval to accommodate such ADUs in a design where one or both of the ADUs is attached to its respective primary dwelling unit.

Determinations of allowable size of an ADU on a specific lot must account for site specific harmonizing between State ADU law and the Coastal Act as necessary to protect coastal access and coastal resources.   Per State law, at a minimum the City must accommodate at least the size of an efficiency unit as defined by Health and Safety Code Section 18007 (Government Code Section 65852.2(c)(2)(A)); and maximum size of 850 square feet or 1,000 square feet for an ADU with more than one bedroom (Government Code Section 65852.2(c)(2)(B)). An attached ADU shall be limited to a maximum of 50% of the size of the primary dwelling unit if there is an existing primary dwelling unit (Government Code Section 65852.2(a)(1)(D)(iv)).

For greater certainty and local control, the City is in process of bringing forward a local ADU ordinance that will take effect following Planning Commission review, City Council review and adoption of an ordinance, review and approval by HCD, and final certification by the California Coastal Commission. In the interim, prospective applicants are encouraged to contact the Planning Department for clarification on implementation.

Zones Where ADUs and JrADUs Are Permitted 

ADUs are allowed in zones that allow single dwelling unit or multiple dwelling unit development.   In Del Mar, this includes all of the City’s residential zones and the Carmel Valley Precise Plan Specific Plan (CVPP). 

  • A lot with a single dwelling unit is permitted to have a maximum of one ADU and one JrADU. The JrADU must be located within the walls of the primary dwelling unit. In addition to the JrADU, one detached ADU is permitted within either a new detached structure or within an existing detached accessory structure that is converted to an ADU. Alternatively, a single dwelling unit lot is permitted to have either one ADU within the walls of the primary single dwelling unit or create one attached ADU within an addition to the primary single dwelling unit; however, in these two examples a JrADU would not be allowed. JrADUs are not allowed within a detached ADU and a maximum total of one ADU is allowed under all scenarios. The primary dwelling unit in all scenarios can be an existing or proposed structure.
  • An existing duplex (two units on one lot attached or unattached) is permitted to have a maximum of two ADUs per lot. The primary dwelling units must be existing. Each primary dwelling unit can have one ADU that is detached or attached from the primary dwelling unit per the development standards that are applicable to ADUs on lots with a single dwelling unit. . If necessary to protect coastal access and coastal resources, such ADUs may be accommodated in a design where one or both of the ADUs is attached to its respective primary dwelling unit however, the ADUs cannot be attached to each other. The City’s Coastal Development Permit findings may be used in this case to justify accommodation of attached ADUs in this scenario.
  • A lot with existing multiple dwelling unit development that includes three or more dwelling units (i.e. RM-South) is permitted to incorporate ADUs into spaces that are not located within the dwelling units themselves. This type of ADU may be constructed within existing multiple dwelling unit building spaces that are not associated with an individual dwelling unit (i.e. common area storage rooms, boiler rooms, attics, basements, or parking garages). The maximum number of ADUs in converted space of multi-dwelling unit buildings is 25 percent of the total number of existing dwelling units on the lot. In addition, up to two additional ADUs may be located on multiple dwelling unit lots as detached structures (maximum of two detached ADUs per lot).

 JrADUs are allowed only in single dwelling unit zones, which within the City of Del Mar include the CVPP, R1-10, R1-10B, R1-14, R1-40, R1-5, and R1-5B zones. Only one JrADU is permitted per lot.

How to Apply

State law requires a streamlined, ministerial review process for proposed ADUs and JrADUs that exempts all such applications that meet each of the specified objective review standards from discretionary permit review, including design review.

Applicants will need to fill out an ADU Application Packet (Fillable PDF), pay associated fees (PDF), and submit development plan sets. Submitted applications will be processed in accordance with the City’s procedures for approval of administrative Coastal Development Permits per DMMC Section 30.75.080.  Submitted plans that meet the requirements of Government Code Section 65852.2 will be approved within 60 days of a complete application submittal. If the ADU or JrADU permit application is processed at the same time as a permit application for a new primary dwelling unit on the lot, the City may delay acting on the ADU or JrADU application until the City acts on the permit application for the primary dwelling unit.

Benefits of ADUs/JrADUs

  • Can provide a greater balance of housing options and affordability to meet the City’s housing goals
  • Can provide more affordable housing options for seniors and lower-income individuals to remain in the community
  • Can provide independent accommodations for extended family or caregivers to live on the same premises
  • Can provide the opportunity for supplemental rental income to homeowners
  • Can help to reduce local vehicle miles of travel (VMT) and meet Climate Action Plan goals by accommodating a greater variety of housing options in close proximity to services and employers within the community