Development in the second row without a development plan? What can we do?

Yes, stupid – in Italy everyone would have simply built for their Bambini in the garden and then wondered five times a year why everything was underwater. And in China, the whole neighborhood would have been relocated to the Mongolian border to build a Corona clinic at the cheap transport hub.

Thank you, I am aware of the advantages of legal certainty in Germany. That’s why I said “for us unfortunately” to indicate the limitation. But back to the topic…

Building eligibility in the second row has been promised, it’s just not achievable in the short term. If you stay on the ball with the decision-makers and maybe find one or two supporters among the neighbors, you can get started in five years, so before the first child starts school.

Sure. Waiting until the development plan is ready is of course one of the other options. But then an interim solution (rental house) would be necessary. Our current apartment as well as the two planned apartments in the rental building by the uncle in case of possible second-row development are already too small for one child.
That’s why my initial question was whether or what else can be done so as not to have to wait for the development plan to be drawn up (see initial post), so that the interim solution does not have to be organized. And you had already assessed that as difficult in your first post.

Two apartments of the rental building are already too small for one child.

I'm completely at a loss here.

I'm stumped.

Assuming that we can build on the property in the second row, a two-family house (one apartment on the ground floor + one on the upper floor) will be built at the front by my wife’s uncle (see initial post). The plans for this are basically already done. And according to §34 of the Building Code, such a house should also easily get a building permit if a development plan is not yet in sight. That is also what the lady from the municipality said: "Build at the front first and then possibly at the back later." Of course, that doesn't help us who want to build at the back. Moving into one of these two apartments in this house, however, would not be an option for us because both would be too small for us with a child, as we both partly work from home and therefore need one large or two smaller rooms more. Our current apartment is out of the question. Here we share a 9m² office. There would be no room at all for a child. So something bigger would be needed if we want to wait for the creation of a development plan. And as I said: yes, that is of course also an option. But I am looking for a way to skip this intermediate step. And yes: I am aware that this is difficult to impossible.

My remarks about the larger rental building referred to the scenario in which building in the second row cannot be realized in the medium term. Then my wife’s uncle says that he would not divide the property and would build differently (= bigger -> whether it then gets a permit is another matter. But then it is no longer my problem...). That is also understandable.

I'll just ask a really silly question, you don't have to answer if you don't want to: How does your uncle envision this retirement provision? If I roughly consider construction costs and rental income, it's questionable whether one even breaks even during their lifetime.

I'll just ask stupidly, you don't have to answer if you don't want to: How does your uncle imagine this retirement provision? If I roughly consider construction costs and rental income, it's questionable whether you even turn a profit during your lifetime.

He is a branch manager of a building materials company. Quote from him: "I can't stop grinning when I get my payslip." His wife works in human resources at the same company and also earns quite well. No children, they currently live rent-free with their parents. That means: a lot of money comes in monthly and little goes out. So I assume that they will have paid it off by retirement. And then the two will have a comparatively good pension plus rental income. In short: the two manage quite well. Whether building a rental house in their early 50s is really a sensible retirement provision, I’ll just leave it at that. I wouldn’t do it that way. But it’s not my business either.

Whether building a rental property in your early 50s is really a sensible retirement provision, I'll just leave that open.

True. Better to buy. But a rental property is land. Already sensible (but with more than two parties).