When are compensators necessary?

Hello, I know the principle that when piping the heating system with copper pipe (which should be the standard), a compensator must be installed every 10m of pipe length. Sounds logical, I have seen that as well. The question is: is there a standard, a manufacturer’s specification, or something similar that requires this? So, can it be done or is it mandatory? I am also looking forward to knowledgeable answers.

Copper pipe? Who still does that nowadays??

The HLS installer. What should I take then?

You no longer use copper. Actually, only plastic or, I believe, some still use stainless steel.

For heating pipes?? For drinking water, sure, but heating? Are you sure?

Could it be that you are misunderstanding each other? One is talking about the pipes directly at the heater and the other about the pipes in the floor? Here it is at least common that the pipes at the heater are made of copper, those in the floor are these plastic things.