Section 27-2141. Notice

a. The vacate order shall be served upon the owner
  by mailing a copy to the person last registered with the  department  as
  owner  or  agent  by  certified  mail,  return  receipt  requested.  The
  affidavit of an employee or agent of the department, stating facts which
  show that the vacate order was  duly  addressed  and  mailed,  shall  be
  presumptive evidence that such vacate order was duly served.
    b. The vacate order shall be served upon the occupants of the dwelling
  by  affixing  a copy prominently on the dwelling which is the subject of
  the vacate order.