1. Qualifications is a good start - and it's a good idea to phone ahead and ensure they're certified by a recognized inspection authority. A trustworthy inspector will be happy to provide this information.

But just as important is finding out what quality of inspection you can expect from any given property inspector. Two good ways to determine this: (1) ask how long they actually take to do the inspection. Inspections done in only 2-3 hours provide a very limited profile of your prospective purchase; (2) ask if they work independently of realtor referrals. If they do not, they work for the realtor. If they are independent, it's alot easier for a property inspector to spend the required time to do the home inspection right.