Ohio Rev. Code Ann. § 723.50

The owner or possessor of any lot or land in any municipal corporation may dig, or cause to be dug, any cellar, pit, or excavation, to the full depth of the foundation wall of any building upon adjoining lots, or to the full depth of nine feet below the established grade of the street or streets on which such lot abuts, without reference to the depth of adjoining foundation walls, without incurring the liability prescribed in section 723.49 of the Revised Code, and may, on thirty days' notice to adjoining owners, grade and improve the surface of any lot to correspond with the established grade of the street, streets, or alleys upon which such lot or land abuts, without incurring liability.