ADU Regulations in Campbell, California (2026)

Regulations at a glance

Local rules & notes

Fire Sprinkler Trigger in Primary Dwelling: The City ordinance attempts to require fire sprinklers in the primary dwelling if the ADU creation results in the primary becoming a 'new dwelling' under local scope-of-work rules. HCD declares this non-compliant. Building Separation Requirement: The City requires a 10-foot separation between the primary dwelling and the ADU. HCD notes this cannot preclude ADUs created under state exemption. CC&R Deference: The City ordinance states it does not override CC&Rs. HCD corrects this, citing Civil Code 4751 which voids restrictive CC&Rs.

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

Frequently asked questions about ADU regulations in Campbell

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

  In Campbell, the maximum ADU size is typically NaN 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; Campbell may follow state defaults or have local limits. Verify with Campbell planning for your specific lot.

• What are the setback requirements for ADUs in Campbell?

  In Campbell, typical setback requirements are 12 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 Campbell planning for overlay zones or design standards that could affect your site.

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

  In Campbell, 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 Campbell or county planning for your zone.

• Is ADU approval ministerial in Campbell?

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

• Are there parking requirements for ADUs in Campbell?

  In Campbell, parking for ADUs is generally Often waived per state law; check local ordinance. California law often waives parking for ADUs within a half-mile of transit or in certain historic districts. Check with Campbell planning for your address.