When are compensators necessary?

It's also not a problem in the heating sector because there is no pitting corrosion due to hardly any oxygen remaining in the water.

I would throw out water pipes anyway if they are being renovated. In this process, you can also of course throw out the heating pipes and have everything new.

I don't know anyone anymore who still installs copper pipes under plaster or screed today. There are actually no more leaks with plastic.

The crucial question, however, was about the extension of copper tubing on the surface.

You cannot say that in general. The length change is not a problem for the actual pipe but for the endpoints. There you just have to check whether the maximum possible expansion can cause damage there.

I don't know anyone anymore who still installs copper pipes under plaster or screed nowadays. There are basically no more leaks with plastic.

Now you know one. In two weeks there's new copper here, 35mm as supply and return lines to the heating circuit distributors.

Exceptions prove the rule

So what now? It seems no one knows any rules/regulations?