The City of Oakley permits ADUs across most residential zones. Oakley follows both state and local ADU laws, allowing most single-family homes to build one detached ADU and one Junior ADU (JADU) per lot. Multi-family properties may be eligible for multiple ADUs, depending on site conditions.

Oakley aligns with California’s broader ADU legislation but has its own requirements for height, setbacks, and design review.

• Detached ADU: Separate from a single-family or a multi-family residence
• Attached ADU: Attached to a single-family or a multi-family residence
• Conversion ADU: Conversion is an ADU or JADU within an existing or proposed primary dwelling unit (i.e., from existing square footage of a single-family residence or multifamily residence) or within an existing accessory building
• Junior ADU (JADU): Up to 500 sf. in size and is contained entirely within a single-family residence

• Maximum Size:
  
  • Detached: Up to 1,200 sq ft; may increase to 1,200 sq ft based on lot size and lot type (estate lots ≥15,000 sq ft)
  • Attached: Up to 50% of the primary dwelling's size, with a maximum of 1,200 sq ft.
• Setbacks:
  
  • Minimum 4 ft setbacks from the rear and side property lines for detached
• Height Limits:
  
  • Typically 16 ft; 18 ft near transit or for multi-story multi-family lots; 25 ft for attached ADUs or per local zoning limits
• Parking Requirements:
  
  • Additional off-street parking space required (except for internal conversions or JADUs)
    
    • Parking may be in tandem or within setback area if needed

To build an ADU in Oakley, the following approvals are typically required:

• Zoning Compliance Review: Confirm the property is in compliance with the local zoning laws.
• Site Plan and Elevations: Include detailed plans that illustrate the proposed ADU's layout and elevations.
• Architectural Drawings: Submit complete architectural plans explaining the design and construction.
• Utility Letters: Provide letters from water, sewer, natural gas, and electricity providers
• Title 24 Energy Documentation: Include recent title report to check easements or restrictions
• Permit Submission: All documents submitted to the City of Oakley Planning/Building Division
  

Homeowners should also review Oakley’s current fee schedule, utility connection requirements, and fire code compliance.

Permit times are usually 6 to 12 weeks depending on the complexity of the project and workload in the city. Some simple projects can be expedited, whereas those with corrections or requiring additional information may take longer. Having experts familiar with Oakley's ADU process can help make approval easier.

Accessory dwelling units shall be a permitted use in any district where residential uses are permitted. Junior accessory dwelling units shall be permitted in the single-family zoning districts within an existing single-family residence, or as part of a proposed single-family residence. 

For the most current and complete information, refer directly to the City of Oakley.