States create incentive programs to encourage property owners to undertake particular types of improvements that meet the goals of the jurisdiction. Programs typically fall into three broad types: preservation and rehabilitation of historic properties, addition of energy-efficient climate control systems, and installation of equipment and machinery to control pollution and/or conserve energy. In most states, the incentive may be a temporary full exemption, a temporary partial exemption, or a permanent exemption from taxation of the increased value resulting from the specific improvement to the property.