ADU Regulations in San Luis Obispo, California (2026)

Regulations at a glance

Local rules & notes

Lot Coverage Exclusion: A significant portion of an ADU's footprint is excluded from the city's maximum lot coverage calculations. Director's Size Exception: The Director has discretionary authority to allow ADUs to exceed standard size limits up to 1,200 square feet. Guest Quarters Conversion: The city defines 'Guest Quarters' separately but allows for their conversion into ADUs, provided only one ADU or Guest Quarter exists per property.

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

Frequently asked questions about ADU regulations in San Luis Obispo

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

  In San Luis Obispo, the maximum ADU size is typically 1000 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 Luis Obispo may follow state defaults or have local limits. Verify with San Luis Obispo planning for your specific lot.

• What are the setback requirements for ADUs in San Luis Obispo?

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

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

  In San Luis Obispo, 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 Luis Obispo or county planning for your zone.

• Is ADU approval ministerial in San Luis Obispo?

  In San Luis Obispo, 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 Luis Obispo planning can confirm the exact process.

• Are there parking requirements for ADUs in San Luis Obispo?

  In San Luis Obispo, 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 Luis Obispo planning for your address.