Notices or orders issued pursuant to this act shall be served upon the owner or operator by posting them by certified mail, return receipt requested, to the owner or operator of a rooming or boarding house or, if necessary, by leaving them with the owner or a person above the age of 14 at the owner's dwelling unit or place of business. The date of service shall be considered to be the third day after mailing or after the date the notice or order is left at the owner's dwelling unit or place of business.
N.J.S. § 55:13B-12