(A) All buildings erected hereafter, all uses of land or buildings established hereafter, all structural alteration or relocation of existing buildings occurring hereafter and all enlargements of or additions to existing uses occurring hereafter shall be subject to all regulations of this chapter which are applicable to the zoning districts in which the buildings, uses, or land shall be located.
(B) However, where a building permit for a building or structure has been issued in accordance with law prior to the effective date of this chapter; and provided, that construction is begun within 90 days of the effective date and diligently prosecuted to completion, the building or structure may be completed in accordance with the approved plans on the basis of which the building permit has been issued and may, upon completion, be occupied under a certificate of occupancy by the use for which originally designated, subject thereafter to the provisions of § 156.081.
(Prior Code, § 156.004) Penalty, see § 156.999