The 3 – 5 rule is a code requirement standard of the ASME A17.1 for residential elevators.
In 1955, when the American Society of Mechanical Engineers adopted A-17, the first safety code for private residence elevators, it was responding to what was, by then, the well-known problem of excess clearance: “Clearance between the hoistway doors or gates and the hoistway edge of the landing sill shall not exceed two inches and the distance between the hoistway face of the landing door or gate and the car door or gate shall not exceed four inches.”
But in 1981, the standard was revised to allow for five inches of clearance. The gap actually got wider as manufacturers transitioned from flat scissor gates to accordion-style doors. The clearance between the hoistway door and the peak of the accordion could be five inches, but the space could be as much as seven-and-half inches or more in the valleys of the door.
“THE MAJORITY OF ELEVATOR COMPANIES RECOMMEND IN THE STRONGEST POSSIBLE TERMS; (1) that swing door elevators be installed in accordance with the ASME Safety Code requirements; and (2) that any existing swing door elevators having an excessive space as described herein and in the attached brochure be repaired as soon as possible. Until repaired, any swing door elevator with excessive space should be shut down.
REMEMBER: THE EXISTENCE OF AN EXCESSIVE SPACE BETWEEN THE HOISTWAY DOOR AND CAR GATE MAY RESULT IN SERIOUS OR FATAL INJURY!”
ASME A17.1 Rule 220.127.116.11.2 (aka 3” x 5” Rule) of the above referenced code states: Clearance Between Hoistway Doors or Gates and Landing Sills and Car Doors or Gates. The clearance between the hoistway doors or gates and the hoistway edge of the landing sill shall not exceed 75 mm (3 in.). The distance between the hoistway face of the landing door or gate and the car door or gate shall not exceed 125 mm (5 in.).
As every company and their employees have a different opinion as to “where” to measure from or to, especially in true case of plastic hinged accordion type gates and recessed panel doors, It really boils down to what is safest condition to have.
Beginning in 2005, the A-17 committee continually discussed revisions to the clearance section. The committee is composed of representatives of manufacturers, installation company representatives, inspectors and other contributing parties. A minority within the A-17 Committee lobbied unsuccessfully to change it back to the original dimensions. Minutes of the committee meetings between September 2006 and June 2007 show that the majority repeatedly shot down any proposals for tighter clearances and more precisely described measuring points to ensure that home elevators would comply.
At the first quarterly meeting of 2013, the committee was poised to codify the latest revisions, which included measuring instructions that would have allowed designers to consider the shortest point when measuring the clearance, instead of the farthest point. But a member of the larger standards committee made an impassioned and successful plea to reject the change. The standard still calls for no more than 5 inches of clearance, and after seven years of debate, the committee has taken up the issue again.
As Elevator Contractors, we are constantly having to closely work with the contractors to ensure they understand and comply with the 3” part of the 3” x 5” rule. We always recommend they use specific door jambs manufactured specifically for use on residential elevators. This has been and always will be a challenge as hoist-ways, especially multi level or with adjacent or revers openings, need to be perfectly plumb and square. Any variation, no matter how slight, will cause the hoistway/sill/gate clearances to vary and possibly create a non-compliance situation.
As technology progresses, there are newer types of door/gate systems for residential elevators that comply well within the above referenced code.
One solution is a specially manufactured swing door frame that provides a 25 mm (1in.) maximum distance between the hoistway door and edge of the landing sill.
Simply having and automatic accordion gate operator will definitely reduce any possible entrapment issue as the gate will most certainly com in contact with the obstruction and fail to close preventing movement of the elevator itself.
Another solution recently has been the implementation of power side slide doors and gates on residential elevator applications. The tolerances on these are well below the 3” x 5” requirement.
The choice you make in who you hire as your Elevator Contractor should include their safety record as it relates to accidents and their compliancy with the code, whether it is installed in a jurisdiction requiring an inspection or not. Call us at (800)201-1212 today for a free consultation.