Ohio Rev. Code § 153.62
All contracts for the erection, construction, repair, or alteration of any building, highway, or other work or improvement of any nature by an officer, board, or other authority of the state, a county, township, municipal corporation, school district, or any political subdivision, or any public institution belonging thereto, are subject to all applicable federal, state, and local statutes, ordinances, and regulations, including, but not limited to, those dealing with the prevention of environmental pollution that affect or are affected by such contracts. If the bidder to whom the work is awarded must undertake additional work due to the enactment or amendment of statutes or rules occurring after the submission of the successful bid, the awarding body shall issue a change order setting forth the additional work that must be undertaken and authorizing additional cost to the contractor, which shall not invalidate the contract. The cost of such a change order to the awarding agency shall be determined in accordance with the provisions of the contract for change orders or force accounts or, if no such provision is set forth in the contract, then the cost to the awarding agency shall be the contractor's actual costs including wages, labor costs other than wages, wage taxes, materials, equipment costs and rentals, insurance, and subcontracts attributable to the additional activity, plus a reasonable sum for overhead. Such additional costs to undertake work not specified in the invitation for bids shall not be approved unless written authorization is given the successful bidder prior to the successful bidder's undertaking such additional activity. If a dispute arises between the awarding agency and the successful bidder, procedures shall be commenced under the applicable terms of the construction contract, or, if the contract contains no provision for resolving the dispute, it shall be resolved pursuant to the procedures for arbitration in Chapter 2711. of the Revised Code.
R.C. §153.62