In accordance with Ohio R. C. 713.11, the Planning and Zoning Commission may in appropriate cases and subject to appropriate conditions and safeguards authorize such variance from the terms of this Zoning Ordinance as will not be contrary to the public interest where, owing to special conditions, a literal enforcement of the provisions of this Zoning Ordinance would result in unnecessary hardship. No nonconforming use of neighboring lands, structures or buildings in the same district and no permitted or nonconforming use of land, structures or buildings in other districts shall be considered grounds for issuance of variance.