Section 20143 Of Article 3.5. Counties From California Public Contract Code >> Division 2. >> Part 3. >> Chapter 1. >> Article 3.5.

. The board may cause the insertion of provisions in any contract for the erection, construction, alteration, or repair of any public building or structure, or in the specifications therefor, for the performance of such extra work and the furnishing of materials therefor by the contractor as the board, county engineer, or other duly authorized officer requires for the proper completion or construction of the whole work contemplated.