Garden fence: on which side are the fence posts?

Who is actually supposed to build the enclosure? Is it the side neighbor or the front / rear neighbor?

Only a fence will be made on the left and right. There is already a fence opposite.

I don't know who is obligated now, but I don't think enclosure applies on our right.

Since all the neighbors immediately said we will contribute half, everyone was initially happy.

Now it's only about the posts.

Stupid question: If the fence is supposed to stand exactly on the property line, who does it belong to in case of doubt? For example, if the neighbor sells their house and the new owner wants to change something there?

If I were to go somewhere and the fence is on the border with the posts on the neighbor's side, I would think the neighbors built the fence alone and that it belongs to them or that they shared the costs back then.

If the new owner wants to push it, then it would have to be proven that we participated 50% in the fence if the posts are on his half.

If they are on my half, he would basically have to prove that 50% also belongs to him (if the fence transfers into possession upon sale, which I assume for now).

Most fences have a nice side and a usually less nice side, often where the posts are. You now have the choice. Should the hedge see the nice side or you? If there is later a dispute about who owns the fence, it does not matter at all where the post stands. Does it really stand on the boundary, that is 5cm on the neighbor's side and 5cm on yours? Or does it stand entirely on one property? Then it belongs, no matter who paid for it, to the property owner.

Then place the items on the border and the nice side towards you.