In order to select the best renovator for your project, you need the right information. A renovation contractor's past customers are probably the most reliable source of information available to you.
Each renovator you interview should be able to provide references from previous customers. Ideally, these past projects should be similar in scope and scale to yours.
Once you have the list, make the calls. Surprisingly, many people who ask for references never actually follow through and check them. This is a mistake.
Don't feel you are imposing. If the homeowners were not willing to be contacted, they would not allow the renovator to give you're their names.