N.Y. Public Buildings Law § 18

§ 18. Change in contracts. Any change, addition or deduction made in\nany contract by reduction in price, by addition in price or otherwise\nmust be done by an order on contract which may be issued by the\ncommissioner of general services. This order shall specifically set\nforth conditions of the change or other modification and shall be\napproved by the board, department, commission or officer having\njurisdiction. After having been approved by him the order shall be\nforthwith filed in the office of the state comptroller.\n