Where, by reason of exceptional narrowness, shallowness, or shape of a specific piece of property, by reason of exceptional topographic conditions or physical features uniquely affecting a specific piece of the property, or by reason of an extraordinary and exceptional situation uniquely affecting a specific piece of property or the structures lawfully existing thereon, the strict application of any regulations in the zoning provisions of this chapter would result in peculiar and exceptional practical difficulties, or exceptional and undue hardship upon the owner of such property, to grant, upon an application or an appeal relating to such property, a variance from such strict application, so as to relieve such difficulties or hardship.