The City of San Rafael permits ADUs across most residential zones. San Rafael 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 Rafael aligns with California’s broader ADU legislation but has its own requirements for height, setbacks, and design review.

• Detached ADU: An independent living unit located on the same property as the primary residence.
• Attached ADU: An Attached ADU is a unit connected to the main house but partly separate.
• Conversion ADU: ADU created from internal conversion of portions of an existing primary residence.
• Junior ADU (JADU): JADU’s are limited in size to no more than 500 square feet and contained entirely within the single-family structure.

• Maximum Size:
  
  • Detached: maximum floor area of 1,000 square feet
  • Attached: maximum floor area of 1,000 square feet or 50% of the existing residence, whichever is less, except that an ADU with up to 800 square feet of floor area must be allowed.  
• Setbacks:
  
  • Maximum rear and side yard setbacks of a new or expanded ADU, either attached or detached, are 4 feet.
    
• Height Limits:
  
  • Detached ADU: Up to 16 feet in height for a detached ADU on a lot with an existing or proposed single family or multifamily dwelling unit.
  • Attached ADUs: Up to 25 feet for an ADU attached to a primary dwelling or the height limit in the local zoning ordinance that applies to the primary dwelling, whichever is lower.
• Parking Requirements:
  
  • Additional parking is not required if the ADU is:
    
    • The ADU is located within one-half (½) mile walking distance of public transit
    • The ADU is located within an architecturally and historically significant historic district
    • The ADU is located within an architecturally and historically significant historic district.

To build an ADU in San Rafael, applicants must complete:

• Zoning compliance review: Ensures the ADU meets San Rafael’s standards for size, height, setbacks, and parking requirements
• Site plan and elevations: Must clearly show lot boundaries, existing structures, the proposed ADU location, and building height
• Architectural drawings: Include detailed floor plans, roof plans, and exterior elevations for design and code compliance review
• Structural calculations and engineering: Required for any new construction (attached or detached ADU) to verify compliance with California Building Code standards.
• Building permit application: Submit through San Rafael’s Building & Safety Division, including all required plans and documentation.
  

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

San Rafael has no fixed ADU review timeline, but state law requires action within 60 days of a complete application. Actual timing depends on submittal accuracy-missing items like structural or energy reports can cause delays. Pre-approved plans help speed up approval.

ADUs are allowed on lots with an existing or proposed primary dwelling in any residential zoning district in San Rafael. There is no minimum lot size requirement. However, ADUs must comply with applicable setback, height, and access standards, as well as utility and easement regulations. Properties with unpermitted structures or active code violations are not eligible. Sites within flood zones or other restricted areas may require additional review.

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