Construction project and building permit feasible?

The desire for homeownership seems to me to be excessive. Apparently, you would sacrifice a lot for it. What about your wife? Does she see it the same way?

The time for searching for land and planning is a good trial period. Usually, it lasts around 2 years or even longer. During this time, you can let your equity grow significantly. It's best to start right away today.

Building for 5 people is no small matter. But nowhere in the law does it say that 2 children are not allowed to grow up in one room. You could also have all 3 sleep together and use the other room as a playroom or something similar. You could also simply say that 2 children are enough.

With the house you like, you are already well above your 130m² and it lacks a full-fledged bedroom/children's room. You can already see where this is headed. 150m² would be the minimum for five people without a basement. Given the financial situation, I see that as almost utopian.

Neither floor plan A nor B have enough usable space for 5 permanent residents. The room downstairs is more to be seen as a guest room. I know you currently see 4 bedrooms and think "that's fine," but without a plot you don't even know where the front door will be. Building according to the development plan already restricts a lot and can change everything you have thought up in advance. Experienced it myself.

At least the hallway is big enough to fit a stroller.

EDIT: Requirement regarding a 2nd shower on the ground floor not fulfilled!

The discussion is totally pointless since everything is far off.
We searched for 4 years before we finally found something (existing property). Not because money was tight, but simply because nothing is on the market. A plot of land would still be nowhere in sight if we had insisted on building.
I would wait another year, save as much as possible during that time. Then start looking. Discussing square meters and rooms now is pointless. Financing can only be arranged once you have a concrete property.

Yes, partly it is very tedious for me as well. The question was actually whether a loan can be repaid with a rate of 1200 without additional costs. I have to increase the amount to 400,000-450,000. We are definitely searching from now on. Existing properties are not off the table if THAT comes. The bank also says that a precise financing can only be done with the property. But they have also promised us financing. For them, the permanent employment contract that is currently dormant is not a problem.

In 2021, I am in level 4 + intensive care allowance + shift allowance monthly.

I just don't understand why I can let 3 children sleep in one room, but not everyone have a small one. Do you know what I mean?

By usable area, I thought of a shed in the garden. Otherwise, is a garage cheaper than a basement? I still need to think about that.

But she also promised us financing.

Employment contract on hold no problem.