Cal. Health and Safety Code § 19827

(a) The Legislature hereby finds and declares that there is an urgent and statewide public interest in assuring that building contractors comply with the Contractors License Law (Chapter 9 (commencing with Section 7000), Division 3, Business and Professions Code) and provisions of law relating to Workers’ Compensation Insurance for building construction, that property owners are informed about, and protected from, fraudulent representations, liability for worker’s injuries, liability for material and labor costs unpaid by contractors, licensing requirements, and employer’s tax liabilities when improving their property as owner-builders, and that uniformity of enforcement necessitates that the provisions of this chapter apply uniformly statewide. (b) This article shall become operative on July 1, 1980.