This chapter does not prohibit any person, firm or corporation from furnishing, either alone or with subcontractors, labor and materials, with or without plans, drawings, specifications, instruments of service or other data covering such labor and materials:
(a) For store fronts, interior alterations or additions, fixtures, cabinet work, furniture or other appliances or equipment.
(b) For any work necessary to provide for their installation.
(c) For any alterations or additions to any building necessary to or attendant upon the installation of such store fronts, interior alterations or additions, fixtures, cabinet work, furniture, appliances or equipment; provided, such alterations do not affect the structural safety of the building.