No person shall occupy or use or permit the occupancy or use of any building or premises or part hereafter created, erected, changed, converted or enlarged, wholly or partly, until a certificate of occupancy shall have been issued by either the Construction Official or Code Enforcement Officer. Such certificate shall show that the building or premises and the proposed use are in conformity with the provisions of this chapter. It shall be the duty of the Construction Official and/or the Code Enforcement Officer to issue a certificate of occupancy within the time prescribed by applicable state statute.