Before using any building or premises or part thereof hereafter created, erected, changed, converted or enlarged in use or structure or occupancy of vacant land or for a change in the use of land, a certificate of occupancy shall be applied for and duly approved by the City’s duly appointed agent. The certificate will be issued only if such building or premises, or part thereof, and the proposed use thereof conform with the building permit and provisions of this Zoning Ordinance and will be issued only after completion of construction.