Homeowners' Training

Operation  
& Safety

Hall Door To Car Gate Clearances: “3/4 & 4 Rule”

In jurisdictions that have adopted the 2016 or later edition of the ASME A17.1/CSA B44 the requirements to eliminate the potential hazards of entrapment between the hall door and the car gate are more stringent. Referred to as the ¾ & 4 rule, the hall door must not be set back from the inside of the hoistway more than 19mm (.75 in.) for swinging doors and 57 mm (2.25 in.) for horizontal sliding doors. Any type of hall door and car gate combination must not be able to accept a ball greater than 101mm (4 in.) anywhere between the car gate and the hall landing door when both doors are closed.