An overlay zone is a special type of zone which is not necessarily contiguous with other zones, and may be established without regard to existing zone boundaries. Some existing overlay zone types in Chico are:

• Airport Environs Zone (-AE) - Varies according to General Plan policies
• Aircraft Operations Zone (-AO) - Varies according to General Plan policies
• Landmark Zone - All districts
• Planned Development Zone (-PD) - All districts
• Resource Management Zone (-RM) - Open Space for Agriculture, Resource Management, and Resource Management Areas
• Specific Plan Zone (-SP) - Varies according to General Plan policies
• Transit Corridor Zone (-TC) - Varies according to General Plan policies
• Special Design Considerations Zone (-SD) - Varies according to General Plan policies
• Fraternity/Sorority Overlay Zone (-FS) - Medium-High Density -14.01 to 22 units per gross acre and High Density -14.01 to 35 units per gross acre