In any zoning district, structures, both principal and accessory, maybe erected on any single lot of record at the effective date of adoption or amendment of this chapter, notwithstanding limitations imposed by other provisions or regulations of this chapter, even though such lots fail to meet the requirements for the area and/or width of the zoning district in which such lot is located. The erection of a structure on such a lot shall, however, conform to front, rear and side yard requirements for the zoning district in which such lot is located. Variances from the governing yard requirements in any zoning district, including but not limited to using the existing foundation and/or footprint of a prior structure, may be obtained only through action of the Zoning Hearing Board.