California ADU Regulations 2025: What You Need to Know

California continues to lead the nation in ADU-friendly legislation. Understanding the current regulations is crucial for homeowners considering garage conversions or other ADU projects.

Key Changes for 2025

Streamlined Permitting

  • 60-day maximum review period for compliant applications
  • Deemed approved if city doesn't respond within timeframe
  • Limited ability for cities to require design changes

Fee Limitations

  • Impact fees capped at actual cost
  • No separate utility connection fees for ADUs under 750 sq ft
  • Standardized plan review fees

Parking Requirements

  • No parking required for ADUs within 1/2 mile of transit
  • Existing garage parking can be converted without replacement
  • Tandem parking acceptable in most cases

Garage Conversion Specifics

Size Limits

  • Maximum 1,200 sq ft for garage conversions
  • No minimum size requirements
  • Height restrictions based on local zoning

Setback Requirements

  • Existing garage setbacks grandfathered
  • 4-foot side/rear setbacks for new construction
  • No setback requirements for existing structures

Owner Occupancy

  • No owner-occupancy requirements statewide
  • Local ordinances cannot require owner occupancy
  • Both units can be rented simultaneously

City-Specific Variations

While state law provides the framework, cities can have additional requirements:

Los Angeles

  • Expedited plan check for standard designs
  • Additional fire safety requirements
  • Specific parking exemptions in transit areas

San Francisco

  • Unique architectural review process
  • Higher seismic standards
  • Special coastal zone considerations

San Diego

  • Streamlined approval for pre-approved plans
  • Climate zone-specific requirements
  • Affordable housing incentives

Compliance Tips

Before You Start

  1. Check both state and local requirements
  2. Verify current zoning designation
  3. Review HOA restrictions if applicable
  4. Confirm utility capacity

During Planning

  1. Use licensed professionals familiar with ADU laws
  2. Submit complete applications to avoid delays
  3. Plan for standard inspection requirements
  4. Consider energy efficiency standards

Common Compliance Issues

  • Inadequate ceiling heights
  • Missing emergency egress windows
  • Insufficient electrical capacity
  • Non-compliant bathroom ventilation

Future Outlook

California continues to refine ADU regulations with upcoming considerations: - Potential tax incentives for ADU construction - Simplified utility connection processes - Enhanced tenant protections - Regional planning coordination

Professional Guidance

ADU regulations can be complex and change frequently. Working with experienced professionals ensures compliance and smooth project completion. Our team stays current with all state and local requirements to guide your project from conception to completion.

Need help navigating ADU regulations for your project? Contact our permit specialists for personalized guidance and support.