1. Uses of land, structures and uses of structures which would otherwise be prohibited under the Zoning and Property Chapters but have been allowed by the granting of an exception or variance or have been allowed as a special permit may continue until such exception, variance or special permit lapses as provided in this section.
2. If any such use of land or of a structure is not commenced within two years of the allowance of the variance, exception or conditional use, whichever is later, or is discontinued for a period of one year, such variance, exception or conditional use shall lapse, and any subsequent use of such land or structure shall conform to the district regulations for the district in which such land or structure is located.
3. In the event the construction of any such structure is not commenced within two years of the issuance of the variance, exception or special permit for such structure, whichever is later, and diligently pursued to completion, such variance, exception or special permit shall lapse, and any subsequent use of such land shall conform to the district regulations for the district in which such land is located. If any such structure is destroyed by any means to an extent of 60 percent or more of its replacement cost at the time of destruction, it shall not be reconstructed; any such variance, exception or special permit for such structure shall lapse; and any subsequent use of such land shall conform to the district regulations for the district in which such land is located.