Oakland, CA Accessory Dwelling Unit Regulations
Oakland classifies ADUs into three categories for One-Family and Multifamily residences, ranging from interior conversions to new detached builds. Junior ADUs (JADUs) require owner occupancy and must be within a One-Family building envelope. In S-9 Fire Safety Protection zones, new ADU construction is prohibited unless an additional off-street parking space is provided and any lost parking is replaced on-site.
In Oakland, an Accessory Dwelling Unit (ADU) is defined as an interior, attached, or detached dwelling unit that is accessory to a primary Residential Facility on the same lot. These units must provide complete independent living facilities, including permanent provisions for living, sleeping, eating, cooking, and sanitation [Section 17.09.040].
Types of Accessory Dwelling Units
Oakland categorizes ADUs based on the type of primary residence and the method of construction.
Junior Accessory Dwelling Units (JADU)
A JADU is a specific type of unit contained entirely within the building envelope of an existing or proposed One-Family Residential Facility.
- Location: Must be within the main residence; conversions of detached or attached accessory structures are not permitted.
- Requirements: Must contain an efficiency kitchen. It may have separate sanitation facilities or share them with the primary unit.
- Occupancy: The property owner must occupy either the JADU or the primary residence.
- Deed Restriction: A deed restriction must be recorded to enforce the owner-occupancy requirement [Section 17.09.040, Category A].
One-Family Residential ADUs
For lots containing a One-Family Dwelling, ADUs are split into two categories:
- Category One: A conversion of existing space within the primary residence or a legally existing associated accessory structure. This may include rebuilding an existing accessory structure according to specific standards.
- Category Two: A newly constructed attached or detached unit. This includes exterior additions to the primary residence for the purpose of creating the ADU [Section 17.09.040, Categories B–C].
Multifamily Residential ADUs
For lots with Two- to Four-Family or Multifamily Dwelling Facilities, ADUs are classified into three categories:
- Category One: Conversion of legally existing, non-habitable space (e.g., storage rooms, boiler rooms, attics, or basements) located within the existing portions of the facility. This category excludes the conversion of existing residential units, commercial space, community rooms, gyms, or detached accessory structures.
- Category Two: Newly constructed detached units or the conversion of legally existing detached accessory structures. Converted units must stay within the existing building envelope or be rebuilt to the same exterior dimensions.
- Category Three: A single unit created through new construction (interior or attached) or the conversion/rebuilding of an attached accessory structure [Section 17.09.040, Categories D–F].
Regulations in S-9 Fire Safety Protection Combining Zones
Specific restrictions apply to properties located within the S-9 Fire Safety Protection Combining Zone to mitigate fire risks.
Prohibited ADU Types
The following are prohibited within the S-9 zone:
- Category One ADUs (One-Family or Multifamily) that involve conversions of space outside the envelope of an existing Residential Facility.
- More than one Category One ADU within the existing envelope of a Multifamily Facility per lot.
- All Category Two ADUs (One-Family and Multifamily).
- Multifamily Category Three ADUs [Section 17.88.050, A].
Exceptions and Parking Requirements
A prohibited ADU type may be allowed in the S-9 zone if it meets specific parking or accommodation criteria:
- Parking Creation: At least one additional off-street parking space must be created for the ADU. This is in addition to the required parking for the primary residence.
- Parking Replacement: Any parking spaces lost due to the construction of the ADU must be replaced elsewhere on the lot.
- Reasonable Accommodation: Exceptions may be granted through a Reasonable Accommodation Request for occupants with disabilities or live-in caregivers. While no additional ADU parking is required in this case, any lost parking spaces must still be replaced on the lot [Section 17.88.050, B].
General Unit Definitions
- Efficiency Dwelling Unit: A unit with a single habitable room (other than a kitchen) and a total floor area of 400 square feet or less [Section 17.09.040].
- Regular Dwelling Unit: Any unit that is not an Efficiency Dwelling Unit, Rooming Unit, or ADU [Section 17.09.040].
- Building Envelope: The exterior surface of a building (foundation, walls, roof, etc.). An increase in the envelope includes increasing the footprint, height, or converting open balconies/decks into living area [Section 17.09.040].