California Code, Civil Code - CIV § 2079

(a) It is the duty of a real estate broker or salesperson, licensed under Division 4 (commencing with Section 10000) of the Business and Professions Code, to a prospective buyer of residential real property improved with one to four dwelling units or a manufactured home as defined in Section 18007 of the Health and Safety Code, to conduct a reasonably competent and diligent visual inspection of the property offered for sale and to disclose to that prospective buyer all facts materially affecting the value or desirability of the property that an investigation would reveal, if that broker has a written contract with the seller to find or obtain a buyer or is a broker who acts in cooperation with that broker to find and obtain a buyer.

(b) It is the duty of a real estate broker or salesperson, licensed under Division 4 (commencing with Section 10000) of the Business and Professions Code, to comply with this section and any regulations imposing standards of professional conduct adopted pursuant to Section 10080 of the Business and Professions Code with reference to Sections 10176 and 10177 of the Business and Professions Code.