California Code, Health and Safety Code - HSC § 17923

(a) The provisions of Section 17922 are not intended to prevent the use of any material, appliance, installation, device, arrangement, or method of construction not specifically prescribed by this part, the building standards published in the State Building Standards Code relating thereto, and the other rules and regulations promulgated pursuant thereto, providing such alternate has been approved. The department may approve any such alternate if it finds that the proposed design is satisfactory and that the material, appliance, installation, device, arrangement, method, or work offered is, for the purpose intended, at least the equivalent of that prescribed in this part, the building standards published in the State Building Standards Code relating thereto, and the other rules and regulations promulgated pursuant thereto in performance, safety, and for the protection of life and health.

(b) Whenever there is evidence that any material, appliance, installation, device, arrangement, or method of construction does not conform to the requirements of this part, the building standards published in the State Building Standards Code relating thereto, and the other rules and regulations promulgated pursuant thereto, or in order to substantiate claims for alternates, the department may require tests as proof of compliance to be made at the expense of the owner or his agent.