Hello Waldi,
Joerg is completely right about that.
Provided that this is not an agricultural retiree property, such a project would be pretty hopeless.
Here is the path roughly outlined:
First of all, there would have to be a public interest. This would then be discussed and voted on in the municipal building committee.
If there is a majority decision, the building administration would be commissioned to draft a development plan. The responsible building regulations office of the city or district would also be consulted for this.
The development plan then goes back to the building committee for consultation and further voting.
If everything goes its course, it must be publicly posted.
There are objection periods from citizens for this.
Only then can it be submitted to the municipal council for the final vote and approval, so that it becomes legally binding after the corresponding periods.
Only after this can development begin, the costs of which will later be partially passed on to the neighbors.
It takes many, many months or even years for such a procedure to go through all instances, always assuming that everyone agrees by majority. That’s a piece of democracy.
For a single plot of land, one will hardly initiate such a procedure, unless there is a public interest serving the common good.
I would also look out for a building gap in your place.
Neighbors usually know who owns the property; asking costs nothing.
With a bit of luck, you might then get a building lot and perhaps already know the future neighbors, whom dear God gives you as a gift.
Regards, Danton