The City of San Leandro permits ADUs across most residential zones. San Leandro 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.

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

• Detached ADU: separate from the main house, typically located in the backyard
• Attached ADU: A unit that is attached to the main single-family home
• Conversion ADU: An ADU created by converting existing legal space, such as a garage, basement, or a portion of the primary residence's interior.
• Junior ADU (JADU): A smaller unit of up to 500 sq ft, carved out from within the existing walls of the main home.

• Maximum Size:
  
  • Detached: Up to 1,200 sq ft
  • Attached: Up to 50% of the primary dwelling’s floor area, not exceeding 1,200 sq ft
• Setbacks:
  
  • 10 to 20 ft from side and rear property lines
• Height Limits:
  
  • New detached ADU - 16 ft, but may extend to 18 ft if within ½ mile of transit
  • New attached ADU - 25 ft
• Parking Requirements:
  
  • Additional parking is not required if the ADU is:
    
    • No additional or replacement parking is required 

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

• Zoning compliance review: Ensures the proposed ADU meets local zoning requirements
• Site plan and elevations: Shows property lines, existing structures, proposed ADU location, dimensions, setbacks, and elevations
• Architectural drawings: Includes detailed floor plans, room dimensions, door/window locations, and layout of plumbing and kitchen fixtures
• Structural calculations and engineering: Demonstrates compliance with building codes and structural safety requirements
• Title 24 energy documentation: Confirms the ADU meets California’s energy efficiency standards

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

Permit review times vary but are typically between 12 to 15 weeks depending on project complexity and city workload. Projects requiring corrections may take longer. Engaging professionals familiar with San Leandro’s ADU process can help streamline approval.

Most residential zones are eligible for ADUs, including single-family and multi-family zones. There are no minimum lot size requirements for ADUs. Some properties in hillside or environmentally sensitive areas may have special restrictions.

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