Important: This page summarizes key ADU-related information for San Diego. California has a statewide ADU baseline that all cities must follow, but local implementation details vary. Always verify current requirements directly with the San Diego Development Services Department.
Overview
San Diego has been one of California's most ADU-friendly cities, with active support for companion unit development and streamlined permitting processes. The city has developed comprehensive ADU regulations and established the Companion Unit Program to encourage affordable ADU creation. San Diego's ADU framework reflects both state requirements and the city's commitment to housing diversity.
San Diego's Development Services Department manages ADU applications, including zoning review, plan check, and building permits. The city offers the Companion Unit Program which provides incentives for ADU projects, including density bonus, parking waivers, and fee reductions.
Statewide baseline
California state law creates a baseline that San Diego must follow. Key statewide requirements include:
- ADUs are approved ministerially—local agencies cannot impose discretionary conditional use permits or other discretionary review
- State law sets firm timelines for permit review and approval
- Maximum ADU size is limited by state law (generally related to primary residence size with specific caps)
- Setback requirements are minimized by state law (typically 4 feet from property line for ADUs)
- Parking is not required for ADUs near transit, and significantly limited in most locations under state law
- Impact fees for ADUs under 750 square feet are limited under state law
Local rules and standards in San Diego
Beyond the statewide baseline, San Diego has local standards and implementation details that affect ADU projects:
Companion Unit Program
San Diego's Companion Unit Program provides incentives for ADU development, including potential fee reductions, parking waivers, and density bonus availability. The program encourages affordable ADU creation and streamlined processing. Confirm your project's eligibility and specific benefits with Development Services.
Local ADU ordinance
San Diego has established comprehensive ADU regulations covering size, design, setbacks, and site placement. The ordinance includes standards for both new construction and conversions. Review current requirements with the Development Services Department.
Zoning compliance
San Diego's zoning code includes specific ADU provisions for different zone categories. Residential zones have varying allowances for ADU size, placement, and configuration. Verify zone-specific requirements for your property.
Utility connection standards
San Diego has streamlined utility connection processes for ADUs. Water, sewer, and power connections follow standard procedures that have been adapted for ADU projects. The Development Services Department can outline utility connection requirements.
Affordable housing incentives
San Diego offers density bonus and other incentives for ADUs rented at affordable rates. These incentives may include parking reductions, setback relief, or fee waivers. Discuss affordable housing options with Development Services during project planning.
San Diego-specific notes
- San Diego has been recognized as one of California's most ADU-friendly cities with high ADU development activity
- The Companion Unit Program offers significant support for ADU projects, including fee assistance and density bonus
- Development Services maintains detailed ADU resources and regularly updates ordinances to align with state law
- San Diego's climate and diverse neighborhoods provide opportunities for various ADU types and designs
JADU rules
JADUs in San Diego follow state law requirements and may be eligible for Companion Unit Program benefits. The unit must be contained within the primary home, limited to 500 sq ft of interior space, and owner occupancy of one unit is required. Contact Development Services for JADU eligibility and program benefits.
SB 9 in San Diego
San Diego has been actively processing SB 9 applications as part of housing diversification efforts. SB 9 allows lot splits or dual units in single-family zones under specific state conditions. Verify SB 9 eligibility and processing timelines with Development Services.
Title 24 and energy code
ADUs in San Diego must comply with California Energy Code (Title 24) like all new residential construction. The permit application date determines which energy code cycle applies. San Diego's moderate climate affects energy code compliance pathways. Work with an energy consultant familiar with San Diego's climate zone.
Practical tips for San Diego homeowners
- 1Contact Development Services to discuss Companion Unit Program eligibility and potential fee benefits
- 2Request a preliminary zoning check to confirm ADU allowances for your property
- 3Inquire about affordable housing incentives if renting the ADU at below-market rates interests you
- 4Confirm parking requirements and whether parking waivers are available through the Companion Unit Program
- 5Discuss utility connection requirements and timeline with development services
- 6Consider pre-application conference to clarify expectations and streamline permitting
Official links
These are the official San Diego resources for ADU information:
What to verify before starting
Before beginning an ADU project in San Diego, verify the following directly with the San Diego Development Services Department:
- Companion Unit Program eligibility and specific benefits available for your project
- Your property's zoning and ADU allowances
- Parking requirements and potential waivers
- Utility connection requirements and costs
- Current permit fee schedules and any available fee reductions
- Design or aesthetic standards for your area
This page is for general educational purposes only. San Diego ADU rules, local implementation, and code requirements can change. Always verify project-specific requirements with the San Diego Development Services Department, San Diego County, and qualified professionals.