most counties you can't get a Certificate of Occupancy on a home without power, water and sewage. You can't just build a house. you have to file the permits with the county, have it inspected and have the county issue a certificate that it is fit for habitation.
and if you are buying an existing home the bank will force you to pay for an inspection, they will check FEMA flood maps and the resale values before they write you a check to protect their investment. and a lot of people will hire a real engineer instead of an inspector for a more detailed inspection because a lot of states have weak laws and existing owners will try to hide a lot of major problems