The service of any order to remedy a violation of the Fire Prevention Code may be made upon the occupant of the premises to whom it is directed, either by delivering a copy of same to the occupant personally, or by delivering the same to, and leaving with, any person in charge of the premises. Whenever it is necessary to serve such an order on the owner of the premises, such an order may be served either by delivering to and leaving with the owner a copy of the order, or if the owner is out of the jurisdiction of the inspector making the order, by mailing the order to the last known mailing address of the owner.
(`90 Code, § 8-31)