Terrace wall to the neighbor - What should we consider?

Hello forum members,

we want to separate our terraces from the neighbor, who without our consent has made the lowest row of concrete in the middle on the boundary, which is 17.5 cm wide, and has built his terrace. Now you can basically build the wall centered on the boundary with a maximum thickness of 17.5 cm.
The wall will be 180 cm high and 3 m long. It will be anchored to the house. I don't have any more details at the moment.

My questions:
Is the wall not too thin with 17 or 17.5 cm?
What do we have to consider? Alternatively, we build a proper wall only on our property, or centered, but then it is more on our property and we use 24 cm wide stones. I have zero experience, does anyone have experience? The whole thing will be plastered white.
Is 180 cm enough height? I would be grateful for any tip.

Tomorrow I will send pictures. We have a corner terraced house and want to separate our terrace from the neighbor. Now he has already built the terrace and laid the foundation for the wall. The foundation is about 17 cm wide and on the property boundary, so it is equally on his and our property. A wall is to be built on it now. What must be considered here? I will gladly send pictures tomorrow; now it is too dark.

Best regards

Does anyone have any information? Or anything to note? Oh yes, the foundation is laid in such a way that 17.5 is paid on it, the word foundation was missing for me.

Has anyone got info? Or anything to note? oh yes the foundation is laid so that you pay 17.5 on top, I missed the word foundation.

Actually, your posting is confusing and I don’t really know what exactly you’re asking or what the problem is. Photos?

I will send pictures tomorrow. We have an end terraced house and want to separate our terrace from the neighbor. Now he has already built the terrace and laid the foundation for the wall. The foundation is about 17cm wide and on the property boundary, so it is equally on his and our property. A wall is now to be built on it. What should be considered here? I will gladly send pictures tomorrow, it is too dark now.

A wall is to be built on that now. What needs to be considered?

1. that a 3m long, 1.80m high, and 20cm wide concrete wall in the garden is pretty ugly? 2. that you should talk to each other? 3. That leads to nothing, one sets the foundation without asking, the other slaps a concrete wall on it without asking...

Here are some pictures.

No, we are not just slapping something on there, we include the neighbor. He only has bad ideas, we want to give him a good offer with a good idea.

It will be plastered. Why should it be ugly?