Construction project and building permit feasible?

Honestly, forget the nonsense right now. Look for a new rental apartment, wait until the full income from 2021 comes, and then everything will be fine. Until then... save (also regarding BAföG debts).

Which bank have you already been with that gave you this statement about not recognizing certain incomes?

In itself, it sounds feasible, although zero equity of course makes things difficult. However, I can also imagine that unfortunately in 2019 outdated thought patterns still linger in people’s minds: "no man in the house, who is supposed to provide personal effort?" or general reservations about the lifestyle model that call into question the long-term viability of the project. I know it’s nonsense, but you can hardly throw that in your financing advisor’s face.

I also can't imagine that it is doable with the income and full financing to find a bank that goes along with it. I don't know the situation in Saarland, but I can't imagine it being much better than in the rest of Germany, meaning: 2 years of searching for land, 0.5 years of searching for a general contractor, 1 year waiting time, 1 year construction time, ergo move-in 2024.

So far I had contact with "my" Sparkasse and the Swabian Hall (where our home savings contract is) and both agreed to financing. However, I asked the wrong question and it wasn't about building yet. In the current situation, both would have financed us. I specifically asked about full financing with a monthly rate of 900-1000€. They said we could easily look up to 250,000.

But whether they would also do a higher monthly rate, I just didn't ask. Sparkasse calculated with 2,500+262+600€ parental allowance (which I deliberately left out now)+408 child benefit. 3,770 - 1,800 flat rate for 4 people - 400 for cars - 150 BAföG sometime = calculated 1,420€ and therefore said the financing would definitely be possible. And something else with 50,000 KfW...

Which bank have you been to already, where you got this statement about non-recognition of certain incomes?

Basically, it sounds doable, although zero equity naturally makes things difficult. But I could also imagine that unfortunately, as of 2019, historically outdated mindsets are still lingering: "no man in the house, who is supposed to do the labor?" or general reservations about the lifestyle model questioning the long-term viability of the project. I know it’s nonsense, but you can hardly throw that in your financing advisor’s face.

Only at my house bank and by phone with Schwäbisch Hall.

You are probably right. But luckily my house bank knows my whole clan (advantage of living in a small town). They know that my father renovated the whole house alone (including steel beams, tearing down floors and rebuilding, electrics etc.). But he is also getting older, so I don’t want to plan him for plumbing, steel beams, electrics etc. I definitely learned to pitch in with him. He would do tiling and screed as well. My wife and I can do floors, painting, and plastering. Actually, not everyone believes us.

Honestly, forget the nonsense for now. Look for a new rental apartment, wait until the full income from 2021 comes in, and then everything will be fine. Until then... save (also regarding BAföG debts.!)

Everyone agrees with waiting until 2021. I'll adapt.
but a new rental apartment is not an option. The move costs a lot, our apartment is rather below the rent index aside from the fact that with 2 kids and a dog, you end up searching foolishly and pointlessly. What remains are €1000 rent and up. We have regularly looked for the past 3 years - it just doesn't work anymore.

Everyone agrees with waiting until 2021. I’ll adapt. but a new rental apartment is out of the question. The move costs a ton, our apartment is rather below the rent index apart from the fact that with 2 children and a dog you look yourself silly and stupid. what remains is 1000€ cold rent and up. After that, we have regularly looked in the past 3 years – that no longer works.

Basically, it doesn’t stop at a rate of 1200€, monthly additional costs for a single-family house also average around 400€, roughly speaking.