Cal. Pub. Cont. Code § 5110
(a) When a project for the construction, alteration, repair, or improvement of any structure, building, or road, or other improvement of any kind is competitively bid and any intended or actual award of the contract is challenged, the contract may be entered into pending final decision of the challenge, subject to the requirements of this section. If the contract is later determined to be invalid due to a defect or defects in the competitive bidding process caused solely by the public entity, the contractor who entered into the contract with the public entity shall be entitled to be paid the reasonable cost, specifically excluding profit, of the labor, equipment, materials, and services furnished by the contractor prior to the date of the determination that the contract is invalid if all of the following conditions are met:
(b) In no event shall payment to the contractor pursuant to this section exceed either of the following: