Deficiencies in the new construction. Dispute over the amount of withholdings.

Please stay reasonable.

I suspect that instead of copper, stainless steel pipes were installed. Steel pipes are completely sufficient and just like stainless steel, they are just as high-quality as copper, if not even better. Therefore, I cannot see any defect here. The thermal expansion of steel pipes is significantly lower. Thus, the installation of the steel pipes could very well have technical and constructive reasons.

In a closed heating circuit, there is no air. Therefore, it cannot rust. Copper is actually rather unfavorable, especially when embedded in plaster.

To now claim 9,250 euros in damages is very cheeky. If I were the contractor, I would offer to replace the pipes. You really don’t want that hassle. What happens then? A rightly irritated craftsman breaks open your walls, possibly damages other pipes, and botches the whole mess by re-installing copper pipes.

Your tiles and grout will become crooked, there will be dirt in the house, maybe the ladder will get caught somewhere and really scratch your front door.

It’s only about your ego. Are you by any chance a teacher?

So just take the 500 euros and let it be. What is that supposed to be?

I would ask your plumber and supply technician friend not about the costs but about the consequences. If you had to replace the pipes 20 years earlier, the current replacement would not be disproportionate in my understanding.

According to his assessment, copper pipes would last 10 to 20 years longer than steel pipes.

Then clarify that again with an expert. If that is the case, you can see further. If not, you are shooting sparrows with cannons.