ADU Regulations in Auburn, California (2026)

Regulations at a glance

Local rules & notes

Auburn/Lewiston Watershed Exception: The state ADU statute explicitly does not apply to lots within the watershed of a water source located in the City of Lewiston or the City of Auburn used for drinking water with a filtration waiver. Rate of Growth Ordinance Exemption: ADU permits do not count toward a municipality's rate of growth ordinance (building caps). Density Calculation Exemption: One ADU per lot is exempt from any density requirements or calculations for the area.

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

Frequently asked questions about ADU regulations in Auburn

• What is the maximum ADU size in Auburn, California?

  In Auburn, 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; Auburn may follow state defaults or have local limits. Verify with Auburn planning for your specific lot.

• What are the setback requirements for ADUs in Auburn?

  In Auburn, 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 Auburn planning for overlay zones or design standards that could affect your site.

• What is the maximum height for an ADU in Auburn?

  In Auburn, 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 Auburn or county planning for your zone.

• Is ADU approval ministerial in Auburn?

  In Auburn, 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; Auburn planning can confirm the exact process.

• Are there parking requirements for ADUs in Auburn?

  In Auburn, 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 Auburn planning for your address.