The average person can’t tell the difference between a good medical diagnosis and a bad one. Neither can this person tell a good tax return from a poorly prepared return. Likewise, the typical homeowner can’t discern good from bad when judging a furnace, window, roof, or siding installation.With little understanding of what we do as contractors, and very few benchmarks for measuring value versus cost, consumers usually see hiring a professional contractor as an unfortunate expense, rather than a solid investment.