New neighbor - do we need to move the oil tank?

We have a hereditary leasehold property in the family. It was rented during GDR times and is located at the end of the world. At that time, it was not common for every centimeter to be measured. There are no fences, only hedges. Now we have a new neighbor. He claims that the oil heating tank stands 10cm on his land.

If that is the case, do we have to dig up the tank and move it 10cm? Or did he buy the land as he saw it, and does the tank have grandfathering protection?

You will probably have to make a deal with him.

He complains that the oil heating tank stands 10cm on his land.

Depending on the quality of the cadastral evidence, this deviation lies within the margins of error, so that it cannot be considered an encroachment. However, if an encroachment has been unequivocally determined, it becomes a question of proportionality, which, if no deal with him is possible, would have to be decided by a court. If moving the tank costs €30,000, but the value of the land occupied is only €50, in my humble opinion no court would rule in favor of the neighbor. However, he is entitled to compensation.

We have already offered the deal several times, as he has also taken on some building defects that affect our land. (e.g. gutters draining onto our land, chimney too low so that we sit in smoke, his driveway directly on the boundary). Unfortunately, he showed up at the boundary inspection appointment with a lawyer. Very strange. What is the lawyer supposed to look at there? I would understand if a surveyor came along, but a lawyer? Now we are going there next week to look for the boundary stones – we'll see.

...He is entitled to compensation, however.

What should that look like? We can't exactly buy 10cm of land. Should we rent the 10cm forever?

It remains his land, you agree on the use by a 10 cm oil tank, as long as this tank is alive. For that, he gets such and such euros in damages for lost enjoyment of the land, this is done in writing, but without the land register and all that jazz. Just a small contract You give me I then give you....