This chapter is enacted for the purpose of safeguarding homeowners, other property owners, tenants, and the general public against faulty, inadequate, inefficient, or unsafe electrical, plumbing, low-voltage wiring, utility contracting, or conditioned air installations. The practice of electrical contracting, plumbing contracting, installing, or repairing, low-voltage contracting, utility contracting, and conditioned air contracting are declared to be businesses or professions affecting the public interest; and this chapter shall be liberally construed so as to accomplish the purposes stated in this Code section.