Oh dear, I didn't think it would be this confusing and take up so much space, I really didn't expect that! ;)
So maybe I need to say a little something to perhaps "untangle" things a bit. The municipality did not come to us saying, "Do you want to build, we’ll turn it into building land," but my brother already inquired 2-3 years ago whether there would ever be a possibility for it to be converted into building land. I also have a close relative who is more or less active in the city council and has therefore heard a lot and has good contacts (that's how I know it is supposed to be converted in April or June).
Because of this inquiry in the past, it just turned out that, in connection with the new kindergarten, we were given the assurance that we may build on part of the property. It is actually only a part and not the entire property. This was also published last year in March in the local newspaper under the city’s resolutions, including markings of the future building land on our property.
The part of the property that is being converted is actually the piece between the kindergarten and the only neighbor, so just this piece (about 2000 sqm in total), the rest will remain farmland. Therefore, it is also directly on a developed road; we only have to take over the few meters to our property (we're talking just a few meters).
At the meeting at the building authority last year, we were already told in advance that we are quite free in the design since there is not much around us and the two houses directly next door are very different from each other. What we know so far is that we have to observe the tree protection boundary and that the height can be a maximum of 3 stories. But there will certainly be a few other things; I know that. I looked again in the notary documents yesterday, and he is already talking about land with building expectation; I think he must have other sources for that. I have another appointment there next week (regarding the land register entry of the property), maybe I will find out something else then.
It's not urgent for us; I would just think it’s not a bad idea to do a bit of "preliminary work," so that we can start directly at the latest at the beginning of next year after the assurance has been given that it is supposed to be building land in the next weeks/months and road, sewer, etc., are all in place. But I think I'll just wait because there is quite a bit at stake. If it only works out in a year or later, that wouldn’t be a big deal.
Thanks anyway for all the helpful contributions until now; it has already helped me a lot. And you can tell yourself, I am completely new to the subject, hence my clumsiness, which hopefully won’t last long. I will definitely cling to the building authority again and try to get some information. Maybe it was the caseworker’s fault. I was just afraid that too many inquiries would ultimately be to our disadvantage. But maybe it wouldn’t be wrong to ask again!
Best regards