Can we afford / finance a house?

Before the OP speaks up here again - preferably including the completed questionnaire - further discussion only makes limited sense...

This is how hundreds of banks in Germany calculate. Representative table from the banking world.

results in 1600€ with an income of 2500€. I said nothing else..... The table at the end is interesting.... if I have >10k income per month, then I don't discuss living expenses with my bank employee. I don't argue with people whose income I could completely take over.

If I earn 10k, do they assume that I blow 5k of it?

results in €1600 with an income of €2500.

The problem is that the income is actually €2,900 (child benefits are included in household income) and the flat rate then becomes €1,800.
In the end, it is indeed theoretical. But of course, this area must also be properly prepared for supervision.

If I earn 10k, do they assume that I waste 5k?

It is often actually like that. Two leasing contracts for the car and the first 2.5k are gone Eating at a better restaurant, triple-digit every time. Etc.

I recently spoke with a client who plays in the even higher league. The conversation turned to wine. The Château XYZ from 1985 for 2,500€ a bottle would have been really bad. These are the problems of those who really earn better...

What exactly is included in this LHK flat rate? 100€ more per person (at least in the area where the table still shows numbers), that’s not enough. Even for an additional child, there are more costs for food (possibly also in daycare/school), possibly care, clothes, etc. In addition to the flat rate, rent and regular special expenses, e.g. for another loan or retirement provision, are added? I think I also had to specify costs for childcare separately.