Definitely not possible in Germany just like that, there was / is a person who tried it (Marc Freuke, he was on TV quite often so I feel comfortable sharing his name) and got sued by the municipality. Building code here is already vicious, development plans are just as bad. You are not at all allowed to built on basically everything that is deemed "outside"/outskirts, there are some exceptions but a Jurte or Tipi or cabin is usually out of the way. Even if you own the land. Of course, it is a bit more complicated than that but that is the gist of it.

In essence, you will have a hard time trying to do this.