Ohio Rev. Code Ann. § 5709.51
(A) The legislative authority of a municipal corporation, a board of township trustees, or a board of county commissioners may amend an ordinance or resolution adopted in accordance with division (B) of section 5709.40, section 5709.41, division (B) of section 5709.73, or division (A) of section 5709.78 of the Revised Code, as applicable, to extend the exemption from taxation of improvements to the parcel or parcels designated in the ordinance or resolution for an additional period of not more than thirty years if all of the following conditions are met: