Expensive plot + single-family house 155 sqm + cellar KFW40+, financeable?

It is one perspective. The other: costs are rising. Wood costs more, the IG Bau is negotiating due to higher salaries, etc. Potentially making the new construction more expensive in a year. Obviously, they will probably start with the salary increase. In any case, that is what a BU says. Of course, I would say that too if I wanted to sell something.

May I ask why you wouldn’t grant a loan?

The house value does not cover the loan amount if it has to be sold by the bank.

That’s one perspective. The other: Costs are rising. Wood costs more, IG Bau negotiates for higher wages, etc. This potentially makes new construction more expensive in a year.

If the coming years are like the past, then that is correct. The times are crazy.

Then simply secure the plot of land now. For the "shortfall" from the equity to the purchase price, you can easily get a loan. Then you have already protected yourself against the increase in land prices, and the plot of land is practically equity. If it doesn't work out in the end, the plot will surely be easy to sell again.

Then plan calmly and after the wife's re-entry, construction will begin.

Or are there plots like sand by the sea in your area and you will easily find a nice building plot even in two years?

Although even with €6200 income, the €675k loan (which is currently targeted) is quite a chunk, it is still borderline. But by then, you will hopefully have already paid off some of the plot.

Then just simply secure the plot now. For the "shortfall" from equity to the purchase price, you can easily get a loan. Then plan calmly and after the wife's re-entry, the construction will start. Or are there plots in your area like sand by the sea and you can easily find a nice building plot even in two years?

No, you are absolutely right and so are the others here. We will try to buy the plot, provided we come to an agreement with the seller. Plots are no longer available here (as almost everywhere). But due to the high response here, I assume that our "problem" is also one that many have.

Why is the OBJECTIVE from the bank's perspective? Even with a friend who is a civil servant, the bank did not care that she can of course resume work with any number of hours after 1 year without any problems. This is not a lottery win, but a probability of 99.99%.

Correct, you are talking about a probability. And banks rarely calculate with that. Is the income AVAILABLE NOW for the loan approval or is there a written agreement to resume at time X? If not, it is only a possibility, but not a reliable statement. And the bank relies on facts as of today, not so much on "probably", "maybe", "let's hope". You can also say that property values have increased by 3% every year for the past 20 years. Then the probability that it will develop the same way in the next 20 years is quite high. Still, you only get financed for the current value, not the value in 20 years.

And the bank relies on facts as of today, not so much on "probably," "maybe," "let's hope so."

It's actually quite astonishing how well the closely "related" insurance industry knows about probabilities. Presumably, the default risk for a couple with two children, where one partner can work more again within a defined period, is lower than for a couple (still) without children, who manage the financing with two incomes just barely, but within a foreseeable time (at least within the financing period) will lose one income.

Maybe it would be a business idea to sell such statistical forecasts to banks ;-)