Section 27-498. Application

This section shall apply to the construction,
  alteration, and  use  of  all  outdoor  signs  and  display  structures,
  together with their appurtenant and auxiliary devices.
    (a)  No  sign  may  be  hung or attached upon or on the outside of any
  building unless such work is performed by or under the supervision of  a
  licensed sign hanger.
    (b) No sign shall be erected until a permit therefor has been obtained
  from  the  commissioner in accordance with the provisions of article two
  of subchapter eleven of this chapter.