Where, by reason of exceptional narrowness, shallowness or shape of a specific piece of property, or by reason of exceptional topographic conditions, or by reason of other extraordinary and exceptional situation or condition of such piece of property, the strict application of any regulation in the zoning provisions of this chapter would result in peculiar and exceptional practical difficulties to or exceptional and undue hardship upon the owner of such property, a variance from such strict application, so as to relieve such difficulties or hardship; where in an application or appeal relating to a specific piece of property the purposes of this chapter would be advanced by a deviation from the zoning requirements of this chapter and the benefits of the deviation would substantially outweigh any detriment, grant a variance to allow departure from any regulation in the zoning provisions of this chapter; provided, however, that no variance shall be granted under this subsection to allow a structure or use in a district restricted against such structure or use, and further provided that the proposed development does not require approval by the Planning Board of a subdivision, site plan or conditional use approval.