The neighbor built foundations for a retaining wall on our property.

Hello,

I need a few opinions.

Our neighbor started building in the spring. We have only just started now.

Since the plots have a slight slope, he needs a retaining wall for his garage. Without asking us or giving notice, they excavated about 2 meters into our plot for the said wall. We only noticed this by chance and confronted them about it. We then met on site and talked about it. It was okay with us because we could also straighten out a bit.

Then nothing happened for a long time. The excavated area on our plot was filled in by them. Now they have built their garage and retaining wall, and the foundations of the wall are completely on our property. Again, without asking or giving notice.
They probably also did not intend to fill it properly because when we pointed out that there should be at least a drainage system, both turned red and started to stutter...

We have now asked the municipality. Actually, a land charge should be registered in the land register here because it is not our retaining wall. But this is a burden and would mean a reduction in the value of the plot.
A private contract would have no legal binding here.
We could also demand a restoration.

Now good advice is expensive.
If something needs to be repaired on the wall in 10 or 20 years, it can only be done through our property. Our garden is not that big, and of course, we do not want them digging up the edge of the property then. And who will cover the costs of restoring the garden?

On the one hand, these are all hypothetical things that could happen.
On the other hand, it annoys us enormously that all this was done without our questions and consent.

I don’t want to start the neighborhood off with trouble right away, but I don’t want to put up with it either.

Everything is kind of annoying.

So, what would you do or advise us?

Thank you and sunny greetings

Ambrosia

Just go over with a bottle of beer and explain your concern. Not at your place, so they can't run away, but at theirs. That can be sorted out reasonably.

A private contract would have no legal binding here.

That is not true. The correct statement is that it is safer with land registry entry.

We could also demand a dismantling.

If it is more than a decimeter, you should do that.

On the other hand, it annoys us immensely that all this took place without questions and our consent.

If they did not understand the first time, maybe costs will help to create understanding.

I do not want to start with trouble in the neighborhood right away

Too late. The neighbors have preceded you.

but I also do not want to tolerate this.

Correct. However, the dimension of the encroachment is missing, so that it does not turn into principled obstinacy out of proportionality.

That reminds me of

Correct. However, the specification of the dimension of the superstructure is missing so that the proportionality does not turn into pedantry.

It is segmented.
The foundation is twice 1/2 meter each over a length of twice approximately 5 m.
So it is foundation, garage, foundation.

If you let everything go now, they will always do whatever they want!