How can you find out who the owner of a house is?

We have both here...

It can be summarized. But in principle, two different tasks are behind it. The cadastral/surveying office of the municipality is responsible for the surveying of parcels and maintenance of the (geo)data. The land registry office is located in the district court and manages the land register and the ownership rights recorded therein, changes to the same, etc.

The cadastre is public, the inspection of the land register is restricted. I do not believe that an interested party will gain inspection, but only someone involved.

However, I can imagine that smaller municipalities work hand in hand and forward the requests. An inquiry to the land register office is therefore forwarded to the cadastre office.

I have also called the land registry office before; they do not provide information. I was basically laughed at, told what I think I’m doing. You only receive information if you have a legitimate interest. For example, if a tree from this property falls onto yours or something similar.

At our land registry office it works like this. You go there, say you are interested in buying, and then the owner is sent a letter with your contact information and can decide whether or not to contact you. But it really seems to vary from office to office...

Otherwise maybe not ask the neighbors but the owners of the neighboring houses? So first ask the neighbors about the owners of their rental houses and then ask those owners about the neighbor? Or... as far as I know, for example these neighbors have a legitimate interest in knowing who their neighbor is. They should be allowed to inquire? (At the land registry office)

I don't know what you have in mind? Do you want to buy the place and rent it out? The neighboring owners would surely be interested in having an empty shack in the neighborhood become nice and well-kept again?