Is building a house possible with our savings and financing?

Our house would cost 162,000 € ready for technical installation (i.e., everything including sanitary and electrical). In owner’s labor, there are still wall, ceiling, and floor covering works (including tiles). Additionally, all the connection fees apply. Construction power/water will be provided by my father. The family will pay for the kitchen and bathroom. The house would have 130 sqm of living space, fully equipped with underfloor heating, heat pump, and KW 70.

What do you want to pay for wallpaper, flooring, and exterior facilities with?

What exactly do you mean by that? Additional costs eat up the remaining €38,000 :o?

The big keyword: Additional construction costs.... with us, that's now almost 45,000, of which 12,000 are unusual. These are not included in the price of your house. Also, the 162,000 is only an initial price. Every change will cost you money, and probably more items will come up that are absolutely necessary but not done by your house manufacturer. Things like an entrance staircase, base plaster, splash protection around the house, standpipes for the gutters, road closures (if necessary), and so on. You can easily sink several thousand euros here alone :D

- a house should not become a prison! The loan installment (without additional costs) should never exceed 25% OF available net income, with additional costs no more than 35%. Why only net? Quite simple: second child -> wife on parental allowance for 1 year, for some reason she has to stay at home the second year as well -> financing failed.

Your 25% rule may apply to part of the population, but certainly not to everyone. Financing is quite individual. For such cases you mentioned, one should also have a certain reserve in the account. Combined with a reduction of expenses, sometimes a year has to be bridged. We both earn about 2000€ net. According to your calculation, our installment should be 500€. Then I wouldn’t even think about building a house. I believe one should simply see which costs are fixed costs (installment, insurance, etc.), which costs are variable, and what expenses can be omitted in an emergency. For a foreseeable period like 1 year of loss, in that year I can’t take a big vacation or may not be able to save much for future major repairs on the house. It’s different if due to long-term unemployment/illness/disability a salary fails completely, then I have to see whether I can still afford, for example, 2 cars permanently. For us, we have set an installment that we can cover in an emergency with 1x disability pension and 1x unemployment benefits. Then, of course, no second car and no vacation is possible anymore. Still, the installment is quite a bit higher than 500€.

25% is already a lot, it can't really be implemented like that – especially not if both earn differently.

What I also doubt is the breakdown of your calculation regarding the property transfer tax.

Grunderwerbsteuer (5%): 162tsd Euro ergeben 8.100Euro

As long as the house is not built by the same company from which you buy the land, this tax does not apply. You only pay the property transfer tax on both the land and the (not yet built) house together.

However, this doesn't really improve the situation for the original poster.