ADU Regulations in San Diego, California (2026)

Regulations at a glance

Local rules & notes

Unlimited Bonus ADUs: In Sustainable Development Areas, the number of bonus ADUs is unlimited if qualifying deed-restricted affordable units are provided. Accessible ADU Home Incentive: One additional market-rate accessible ADU is permitted if at least two affordable ADUs are proposed on the premises. Zero Setback Encroachment: ADUs 16 feet or shorter can ignore standard side and rear setbacks and build directly to the property line.

For the official ordinance and latest updates, check your city or county planning department.

Frequently asked questions about ADU regulations in San Diego

• What is the maximum ADU size in San Diego, California?

  In San Diego, the maximum ADU size is typically 1200 square feet, depending on whether the unit is attached or detached. California state law allows up to 1,200 sq ft for detached ADUs and 800 sq ft for attached in many jurisdictions; San Diego may follow state defaults or have local limits. Verify with San Diego planning for your specific lot.

• What are the setback requirements for ADUs in San Diego?

  In San Diego, typical setback requirements are 0 feet from the side property line and 0 feet from the rear. These may be reduced to 4 feet under California Government Code § 65852.2 where applicable. Check with San Diego planning for overlay zones or design standards that could affect your site.

• What is the maximum height for an ADU in San Diego?

  In San Diego, the maximum height for an ADU is generally 16 feet. State law often allows up to 16 feet for detached ADUs and up to 25 feet when within 4 feet of the property line in some cases. Confirm with San Diego or county planning for your zone.

• Is ADU approval ministerial in San Diego?

  In San Diego, ADU approval is typically Ministerial (by-right) per Gov Code §65852.2. Ministerial (by-right) review means the city must approve qualifying applications without discretionary review, per California Gov Code § 65852.2. Your project must still meet objective standards; San Diego planning can confirm the exact process.

• Are there parking requirements for ADUs in San Diego?

  In San Diego, parking for ADUs is generally false. California law often waives parking for ADUs within a half-mile of transit or in certain historic districts. Check with San Diego planning for your address.