In a case of a lot where the deed is recorded in the register of deeds' office or laid out on the Official Tax Map of the Township of Berlin, prior to the effective date of this chapter, or is of such irregular shape that the owner would have difficulty in providing the required side and rear yard setback requirements in which such lot is situated, the Zoning Board of Adjustment may modify the requirements of this chapter in accordance with its power as conferred by law and permit a building or structure to be built thereon.