There are many reasons to use a building inspector. Most of them should surround the safety of the people that are going to be inside the building. It is the responsibility of any owner to make sure the people inside a building are protected in every possible way. Failure to do this is not fair to the customers or visitors.
Usually this individual will only come on a couple of occasions. This happens when a structure is first built to verify that it meets with all specifications. Once any building has been cleared, this individual does not return unless there has been a complaint of some type.
It can be vital to verify that there are no dangerous materials used in the construction of the building. It is also important to make sure that any time the area is open to the public there is no danger of injury. Failure to do this would make the individual responsible for the investigation incompetent at doing their job.
It can be extremely costly to work with this type of person. This is because they are going to look for various structural issues within an area. A person will have a certain amount of time to comply with the recommendations before the state becomes more involved in the process.
This is not something that most owners want to deal with. The current economy makes it very difficult to successfully do business for the benefit of individuals who are trying to do things the right way, working with an investigator is beneficial to learn the areas of a structure that need work.