Accessory Dwelling Units (ADUs)

ADU (pixabay.com)

What is an ADU?

Commonly known as a second unit, granny flat, or in-law unit, an Accessory Dwelling Unit (ADU) is defined as "an attached or a detached residential dwelling unit which provides complete independent living facilities for one or more persons." By definition, an ADU includes permanent provisions for living, sleeping, eating, cooking, and sanitation.

What is an JADU?

An Junior Accessory Dwelling Unit (JADU) is defined in California Government Code Section 65852.22 as a unit that is no more than 500 square feet in size and contained entirely within a single-family residence. A junior accessory dwelling unit may include separate sanitation facilities, or may share sanitation facilities with the existing structure. 

Background

During the 2019 legislative session, Governor Newson signed into law a number of new bills related to ADUs. On December 19, 2019, the City Council adopted Urgency Ordinance 19-11 temporarily updating the City’s regulations regarding Accessory Dwelling Units (ADUs) to conform with new state law that became effective January 1, 2020. 

Current Regulations 

The City Council adopted Ordinance 20-02 on May 19, 2020. The ordinance, effective June 18, 2020, sets the following regulations for ADUs:

Streamlined ADUs

  1. Within Existing Space (Single-Family) - ADUs and JADUs
    • The property contains an existing or proposed single-family dwelling.
    • Allowed one ADU and one JADU.
    • The ADU/ JADU has exterior access independent from the existing residence.
    • The existing structure has side and rear setbacks sufficient for fire and safety. If the existing structure complies with the City’s setback requirements, this standard is automatically met.
    • Small (<150 square-feet) addition allowed to accommodate ingress/egress.
    • If a JADU is proposed, it complies with the requirements of Government Code Section 65852.22.
  2. Detached, New Construction (Single-Family) - ADU
    • The property contains an existing or proposed single-family dwelling.
    • The property does not contain another ADU, but may contain an JADU.
    • The ADU is detached from the single-family dwelling.
    • The ADU is new construction.
    • The ADU maintains a minimum 4’ side and rear yard setback, is under 800 square-feet in size, and does not exceed 16’ in height.
  3. Within Existing Space (Multifamily) - ADUs
    • The property contains an existing multifamily dwelling.
    • The ADU is located within a portion of the multifamily dwelling structure that is not used as livable space.
    • The total number of ADUs within the dwelling structure does not exceed 25% of the existing number of primary dwelling units within the structure, provided that all multifamily dwelling structures are permitted to have one ADU.
  4. Detached, New Construction (Multifamily) - ADU
    • The property contains an existing multifamily dwelling.
    • The ADU is detached from the multifamily dwelling.
    • The ADU maintains a minimum 4’ side and rear yard setback and does not exceed 16’ in height.
    • No more than 2 ADUs per lot.

All Streamlined ADUs

  • Parking: No parking space required.
  • Short-term Rental: No short-term rental allowed in streamlined ADUs.

Standard ADUs

All other ADUs that do not meet the standards for streamlined ADUs shall meeting the following development standards:

  • Passageways: To the extent required by California Government Code Section 65852.2, no passageway is required in conjunction with construction of an ADU.
  • Setbacks: 
    • No setback required for an ADU located within existing living area or an existing accessory structure, or an ADU that replaces an existing structure and is located in the same location and to the same dimensions as the structure being replaced.
    • All other ADUs - Minimum 4’ side and rear yard setback.
  • Height: 
    • Attached ADU - In the area between the setback applicable to the primary dwelling and the setbacks applicable to the ADU, the ADU is limited to a maximum 16’ height.Otherwise, the height limits applicable to the primary dwelling apply.
    • Detached ADU - Maximum 16’ height. Detached ADUs located wholly or partially above a garage is limited to 16’ in height in the area between the setbacks applicable to the primary dwelling the setbacks applicable to the ADU and otherwise the height limits applicable to the primary dwelling apply.
  • Size: Maximum of 850 square-feet for a studio or one-bedroom. Maximum of 1,000 square-feet for more than one bedroom.  
  • Parking: Required 1 parking space per ADU, except for units located within 1/2 mile walking distance from transit, that are part of a new single-family residence, or meet other state-specified conditions. No replacement parking required when an existing garage is converted into an ADU. The required parking space may be provided as a tandem space is an existing driveway or in the required setbacks.

Fees

No impact fees are assessed for ADUs smaller than 750 square-feet. Impact fees for ADUs larger than 750 square-feet are assessed proportionally in relation to the square-footage of the primary dwelling unit. Plan check fees are due for all ADUs. 

Please see the Building Permits page for more detail on obtaining a building permit for an ADU.

Frequently Asked Questions

  • Where are ADUs allowed in Orinda? An ADU may be constructed on any property zoned for residential use. 
  • What if I want to build an ADU combined with another project on my property? For combination proposals, applicants can elect to have the ADU processed independent of the other proposal(s) or as a combined review. If the applicant decides on a combined review, they are voluntarily foregoing the ADU streamlining deadlines. 
  • Is my ADU required to have fire sprinklers? The ADU is not required to have fire spinrklers if fire sprinklers are not required for the primary dwelling.
  • Can my ADU have a separate address? Yes, please contact the Moraga-Orinda Fire District for an address assignment. 
  • What if I want to build an ADU that does not meet one or more of the requirements? Approval of an Variance is required for a ADU that does not meet the regulations. Examples include exceeding the maximum size or exceeding the maximum building height.
  • Do I have to construct a new garage/carport if I convert it into an ADU? No, when a private garage, carport, or covered parking structure is demolished or converted in conjunction with an ADU, the parking spaces do not need to be replaced.
  • My neighbor is building an ADU. Why wasn’t I notified? If an ADU meets the regulations listed above, the application is processed ministerially and there is no neighbor notification requirement.