No person may for a consideration install, alter or restore within the city any insulation or other materials or energy utilization equipment designed or intended to meet the state building code requirements for insulation and energy utilization standards who is not either:
(A) Licensed as a contractor to do the proposed work under G.S. Chapter 87;
(B) Working under the supervision of a registered architect or professional engineer;
(C) An owner working upon his own building; or
(D) Licensed under this article.
(1989 Code, § 7-121)