House construction financing possible in the coming years - experiences?

Don’t let yourself get crazy here. Even if things get tight for 1-2 years, sooner or later the income will automatically increase.

You may have missed it, but ZF is cutting jobs, Varta is practically bankrupt, Intel is massively cutting jobs, etc. etc.... the automatically increasing income is no longer guaranteed in the private sector...

Plan with what you have today. It has to work with that and not with the promotion to boss in 5 years that is promised to you or the belief in the automatic increase in the salary table...

Money worries after building a house are, I would say, the number 1 and 2 reasons for separation. If especially the women no longer remember after moving in that everything was supposed to be done gradually and that you had to skip vacations, etc... then things get rough...

It will be a tight squeeze. You will have a loan installment of just under 2500 euros per month. Construction costs are around 3000 euros per sqm and will continue to rise in the coming years due to the sharply increasing tariff wages in construction. It is becoming increasingly difficult to find construction workers and craftsmen for the project. Relief could only come from interest rate cuts, which remains to be seen. Currently, it seems more likely that inflation will remain persistent and no further cuts are expected in the near future.

Under severe constraints (i.e., loan installment close to 50% of income), it should still be possible, but then you have to know whether it is worth it to you. Nothing can go wrong during construction either.

The question is whether you want to impose a life of relative poverty on your children just so that in 30, 35 years there is a paid-off house. Because you can expect that. With the loan payment, you are like a Hartz IV recipient in the new development area. Including additional costs and reserves, you have 1,500 EUR left to live on. A family on ALG II doesn't have much less. In the end, even the fancy dining table lamp for 250 EUR or the class trip for 500... per child... will not be possible.

Loan installment never more than 30% of net income. We strictly adhered to this for the first (old building) and the second house (new building).

With the loan installment, you are like the Hartz IV recipient in the new development area. Including ancillary costs and reserves, you have 1,500 EUR left to live on. A family on ALGII does not have much less.

With a household income of 5,500€ (she then has to work, before that financing is not to be considered) a rate of just over 2,000€ is quite manageable. But the installment is only possible if you build smaller or contribute a lot of your own work.
Then 3,000€ +X remain for a family's living expenses. Whoever cannot manage that has other problems than the supposedly too high installment.

That is also possible with less. We are four people and manage with regular household fixed costs of 1800 euros. However, I would never calculate with that, as we regularly have annoying special expenses. Class trips, a new children's bike because the old one was stolen and not insured, washing machine repair, veterinarian bill, two complete sets of new school books because both schools are working with new editions this year. Not a month goes by without surprises that reduce the saving and vacation budget. I would always recommend a household book over at least six months before trying to calculate in such borderline areas. You have to KNOW! that the budget works, and not just optimistically estimate that it will work.