Here are a couple FAQs from the ASHI website:
What does a home inspection include?
The standard home inspector’s report will cover the condition of the home’s heating system; central air conditioning system (temperature permitting); interior plumbing and electrical systems; the roof, attic and visible insulation; walls, ceilings, floors, windows and doors; the foundation, basement and structural components.
Why do I need a home inspection?
Buying a home could be the largest single investment you will ever make. To minimize unpleasant surprises and unexpected difficulties, you’ll want to learn as much as you can ...
For more questions and anwers: Welcome Homebuyers and Sellers | ASHI, American Society of Home Inspectors
We had a home inspection after our house was built--just to be sure that everything was fine. And it's a good idea for resale.