Rarely, a state has established a building code that effectively encourages builders to install products that exceed the efficiency of federal standards. This requires the code be designed to avoid preemption by the Energy Policy and Conservation Act. The state of Washington adopted a code that allowed builders to select from multiple compliance pathways listed in an options table, only some of which touched on federally regulated appliances, so that it did not effectively require builders to exceed federal standards. This interpretation was confirmed by the Ninth Circuit. ACEE has written a report on the development of this code and how it avoided preemption issues.