A Building Contractor bond is designed to protect the state against poor workmanship when hiring a contractor. In some municipalities, it is required in order to perform duties for a local or state government. The bond ensures that the contractor will abide by all local and state ordinances. If a contractor fails to execute his or her duties as agreed, they are liable to pay restitution. These bonds are valid for one year, and premiums vary according to the bond amount and the specific project in question. Contractors who are backed by a bond are preferable to many municipalities.