A permit is required to erect, construct, enlarge, alter, repair, move, demolish or change the occupancy of a building, structure or to erect, install, enlarge, alter, repair, remove, convert or replace any electrical, gas, mechanical or plumbing system, the installation of which is regulated by the code. Cosmetic interior remodeling, such as replacement of cabinets, doors, carpeting and plumbing fixtures do not require a permit.