Ohio Rev. Code § 5713.03
The county auditor, from the best sources of information available, shall determine, as nearly as practicable, the true value of the fee simple estate, as if unencumbered but subject to any effects from the exercise of police powers or from other governmental actions, of each separate tract, lot, or parcel of real property and of buildings, structures, and improvements located thereon and the current agricultural use value of land valued for tax purposes in accordance with section 5713.31 of the Revised Code, in every district, according to the rules prescribed by this chapter and section 5715.01 of the Revised Code, and in accordance with the uniform rules and methods of valuing and assessing real property as adopted, prescribed, and promulgated by the tax commissioner. The auditor shall determine the taxable value of all real property by reducing its true or current agricultural use value by the percentage ordered by the commissioner. In determining the true value of any tract, lot, or parcel of real estate under this section, if such tract, lot, or parcel has been the subject of an arm's length sale between a willing seller and a willing buyer within a reasonable length of time, either before or after the tax lien date, the auditor may consider the sale price of such tract, lot, or parcel to be the true value for taxation purposes. However, the sale price in an arm's length transaction between a willing seller and a willing buyer shall not be considered the true value of the property sold if subsequent to the sale:
Nothing in this section or section 5713.01 of the Revised Code and no rule adopted under section 5715.01 of the Revised Code shall require the county auditor to change the true value in money of any property in any year except a year in which the tax commissioner is required to determine under section 5715.24 of the Revised Code whether the property has been assessed as required by law.
The county auditor shall adopt and use a real property record approved by the commissioner for each tract, lot, or parcel of real property, setting forth the true and taxable value of land and, in the case of land valued in accordance with section 5713.31 of the Revised Code, its current agricultural use value, the number of acres of arable land, permanent pasture land, woodland, and wasteland in each tract, lot, or parcel. The auditor shall record pertinent information and the true and taxable value of each building, structure, or improvement to land, which value shall be included as a separate part of the total value of each tract, lot, or parcel of real property.
R.C. § 5713.03