It is always a good idea to hire an inspector when buying a home. Typically when you are doing your walkthrough with your realtor, you're in the buyers mindset. These walkthroughs typically don't last very long. You will be able to pick out the obvious problems that you come across, but its very easy to be distracted while thinking about house plans, size requirements, family needs, etc. A Home Inspection is a very detailed look at the entire home lasting 2-3hrs, done by a trained and experienced inspector. The inspector will be doing things a buyer normally wouldn't, like testing to make sure wiring is proper, examining and using all of the plumbing fixtures, testing the heating system and looking for any signs of structural problems. The inspector will also be using specialized tools most buyers would not have access to such as a moisture meter and a thermal imaging camera. A Home Inspector will be able to determine the year of manufacture on heating units and hot water tanks, giving you an estimate for remaining service life. While not a guarantee or warranty, a thorough Home Inspection done by a professional gives peace of mind to the buyer and can be beneficial to the price negotiation as well.