Cal. Health & Saf. Code § 18015
The provisions of this part apply to all parts of the state and supersede any ordinance enacted by any city, county, or city and county which conflict with the provisions of this part. The department may promulgate regulations to interpret and make specific the provisions of this part relating to construction, titling and registration, occupational licensing, advertising, commercial transactions, and other related or specifically enumerated activities, and, when adopted, these rules and regulations shall apply in all parts of the state. The department may promulgate rules and regulations to interpret and make specific the other provisions of this part and when adopted these rules and regulations shall apply in all parts of the state.
Ca. Health and Saf. Code § 18015