In NYC it is required.

The change comes from RCNY 3610-05 and in 2018 adds a new section of ASME A17.1 Section 2.16.10 And this is what requires "Detection of Overload on Passenger Elevators and Freight Elevators Permitted by 2.16.4 to carry Passengers"

Not sure if this helps but might give you somewhere to start.

Thanks buddy

If your elevator is under the A17.1 2005 code you only have to comply with the code under which the elevator was installed.However, if the elevator has loadweighing on it, it has to work.

Thanks JJ

No it's not required by code. Possibly by a local jurisdiction might require it above and beyond what the a17.1 code requires, like KSNY said new York requires it. Ive got a bunch of jobs that were modded or installed in the last couple years and our area is on the 2013 code currently, none of them have load weighing. I'm not sure if the 2019 code will make it mandatory but I'm pretty sure the 16 code did not. Seems silly if they did since it's not a safety improvement. Possibly a ride quality improvement. But I guess even that depends, it's not a given your ride will be improved with load weighing. All ecospaces have it. I have a hospital of MCE iboxs at 500 fpm 5000 pound capacity cars gearless torin machines with no load weighing and they run much better than ecospaces. And I've never noticed any issue with rollback or jerky starts with empty car or loaded up.

I appreciate your info EE.