The minimum size for push plates is 102 mm (4 in.) in diameter or 102 mm square, and the minimum operable portion for vertical actuation bars is 51 mm (2 in.) wide. Both types of actuators must display the International Symbol of Accessibility.
The most popular type of push button actuator is the surface mount type. It is typically comprised of a back box or mounting box and a push plate containing the actual switch. These are available in hardwired or radio frequency versions. The push plates are designed to fit single or double-gang boxes for flush mount applications. These push plates are also designed to attach to bollards for standalone installations, such as exterior sidewalks. Most button manufacturers provide a number of sizes and shapes, such as square, round and rectangular, typically in 4"and 6" sizes
The 2010 California Building Code requires two push plate actuators at each actuator location: one mounted between seven and eight inches from the floor to the centerline, and the other mounted between 30 and 44 inches above the floor. Vertical actuation bars may be used in lieu of two separate actuators, with the bottom of the bar at five inches maximum above the floor, and the top at 35 inches minimum above the floor. Actuators must be in a conspicuous location, with a level and clear ground space outside of the door swing. The minimum size for push plates is four inches, and the minimum operable portion for vertical actuation bars is two inches wide. Both types of actuators must display the International Symbol of Accessibility.
The use of motion sensors to activate a handicap door is not allowed under ANSI156.19. Once a motion sensor is added to the system then the doorway must be treated as a Full Energy opening and comply with ANSI 156.10. This code requires more stringent safety requirements and will add significant cost and labor to the doorway.