Oakland Accessory Dwelling Unit (ADU) and S-9 Fire Safety Regulations
In Oakland, ADUs generally range from 850 to 1,000 square feet with 4-foot rear/side setbacks. However, in the S-9 Fire Safety Protection Combining Zone, new detached ADUs (Category 2) are prohibited. Properties in the S-9 zone are typically limited to one interior Category 1 ADU or JADU, must provide an additional off-street parking space, and have a maximum height limit of 16 feet.
Accessory Dwelling Units (ADUs) in Oakland are governed by specific development standards regarding size, setbacks, and parking. Additional restrictive regulations apply to properties located within the S-9 Fire Safety Protection Combining Zone to ensure public safety in high-fire-hazard areas.
General ADU Regulations
All ADUs in Oakland must comply with the following basic operational and structural requirements:
- Ministerial Approval: Applications that meet all zoning regulations, including those in Section 17.103.080 and Chapter 17.88, are granted ministerial approval. Review times may be extended if the ADU is part of a larger project requiring discretionary review [Section 17.103.080(A)(1)].
- Rental Duration: ADUs may only be rented for terms longer than 30 consecutive days; short-term rentals are prohibited [Section 17.103.080(A)(2)].
- Kitchen Facilities: Every ADU and Junior ADU (JADU) must have an independent kitchen including a sink, cooking appliances, food preparation counter, and storage [Section 17.103.080(A)(8)].
- Entrances: A separate exterior entrance independent from the primary residence is required. Exterior stairways to upper-story ADUs should not be visible from the front public right-of-way when feasible [Section 17.103.080(A)(9)].
- Sale of Unit: ADUs cannot be sold separately from the primary residence unless permitted by State law [Section 17.103.080(A)(3)].
One-Family Dwelling ADU Standards
The following standards apply to ADUs on lots with a single-family residence:
| Standard | Junior ADU (JADU) | Category 1 (Conversion) | Category 2 (New Construction) |
|---|---|---|---|
| Max Number | 1 per lot | 1 per lot | 1 per lot |
| Max Size | 500 sf | Existing envelope + 150 sf for ingress/egress | 850 sf (Studio/1BR); 1,000 sf (2BR+) |
| Max Height | N/A | Underlying zone standards | 20 feet (unless setbacks of underlying zone are met) |
| Setbacks | N/A | N/A | 4 feet (side/rear) or underlying zone's required setback, whichever is less |
Note: For Category 2 ADUs, the side or rear setback must never be less than 3 feet [Table 17.103.01].
Two- to Four-Family and Multifamily ADU Standards
| Standard | Category 1 (Interior) | Category 2 (Detached) | Category 3 (New Attached) |
|---|---|---|---|
| Max Number | 1 or up to 25% of existing units | 8 per lot (existing); 2 per lot (proposed) | 1 per lot |
| Max Size | Limited by existing envelope | N/A | 850 sf (Studio/1BR); 1,000 sf (2BR+) |
| Max Height | Base zone standards | 18 feet (unless setbacks of underlying zone are met) | Base zone standards |
Note: In the S-9 Fire Safety Zone, the maximum height for any ADU is capped at 16 feet [Table 17.103.02, Note 6].
S-9 Fire Safety Protection Combining Zone Regulations
The S-9 Zone is applied to lots within or adjacent to Very High Fire Hazard Severity Zones (VHFHSZs) accessed by narrow streets (less than 26 feet wide) or long dead-end streets [Section 17.88.010].
Prohibited ADU Types in S-9
Within the S-9 Zone, the following are strictly prohibited [Section 17.88.050(A)]:
- Category 1 ADUs that are conversions of space outside the envelope of an existing facility.
- More than one Category 1 interior ADU per lot.
- All One-Family, Two- to Four-Family, and Multifamily Category 2 and Category 3 ADUs.
Allowed Exceptions in S-9
Development is generally restricted to one interior conversion Category 1 ADU or one JADU per lot [Section 17.103.080(A)(7)]. For an ADU to be allowed in the S-9 zone, it must meet one of these additional conditions [Section 17.88.050(B)]:
- Additional Parking: At least one new off-street parking space must be created for the ADU in addition to all required parking for the primary residence. Any parking spaces lost during construction must be replaced on the lot.
- Reasonable Accommodation: An approved application for disability-related accommodation. No additional ADU parking is required in this case, but any lost parking spaces must still be replaced elsewhere on the lot.
Zoning Amnesty Exclusion
While Oakland offers a "Planning Code Amnesty" program for unpermitted ADUs built before January 1, 2021, this program is not available for units located within the S-9 Zone [Section 17.103.080(A)(14)(f)].
Parking Requirements
- General Rule: One parking space is required per ADU [Table 17.103.01].
- Exemptions: No parking is required if the ADU is:
- Within 1/2 mile of public transit.
- Within an Area of Primary or Secondary Importance (API/ASI) historic district.
- In an area where parking permits are required but not offered to ADU occupants.
- Within one block of a carshare vehicle.
- Part of the existing primary residence or an accessory structure [Section 17.103.080(B)].
- Replacement Parking: If a parking space is removed to build an ADU, no replacement parking is required, except within the S-9 Zone, where lost parking must be replaced [Section 17.103.080(A)(4); Section 17.88.050(B)].