The first step is to ensure that the contractor you have chosen to do you your repairs is licensed and bonded. When it comes to dealing with something as extensive as a whole house fan, you need to be sure you're protected in case something goes wrong. If something were to break while an unlicensed contractor was working on your fan, you would likely be stuck with the complete repair costs. In most states, contractors aren't allowed to operate legally within the state unless they are bonded and insured.

When deciding on the contractor you want to work with, be sure to find out how much they're insured for. A well-formed contract can also be an essential part of making sure that everyone involved with the project has as much protection as is possible. Along with this, you should also consider the importance of working with a contractor who can provide you with references from previous clients for similar jobs.