Error in financing?

Well, I also have the financing completely through TA loans (ok, except for 1x KFW) – the installment remains the same even after the disbursement phase... the whole miserable 30 years long.

And only that was important for us – including the fact that we got the loan and stayed below our maximum expectations with the installment.

I just realized that I logically still have to accrue 1.5% interest on the €50,000, I completely overlooked that. So that's a few euros more, and therefore you can roughly say that the installment doubles.

Hello ! I have now read through the 23 pages. Almost everyone here wants to help you, so you should reconsider the "tone" of your responses a bit. By now, you have realized that you should save up for the additional costs first. That is also a good thing. Afterwards, you should try to calculate the costs (including all accruing additional costs and a buffer). Then you can obtain and compare various loan offers. I have attached an example here with 425,000 euros and a maximum annuity of 2000 euros (in my opinion, however, too high). Compared are an annuity loan with 25 years term (full repayment - variant 1) and a home savings contract construct with 0.4% repayment (variant 2). This is an approximate calculation based on Excel - without guarantee: Note: The yellow fields are assumptions and would have to be adjusted to the actual conditions. At the bottom right, you can see the total repayment amount.

I still don't quite understand the fear of rising interest rates. Assuming a sufficiently high repayment rate of >=3%, I see no risk. Firstly, rising interest rates will be accompanied by significantly increased inflation, and secondly, the remaining debt is so low that one will get significantly better conditions than in the original financing and will also have considerably more flexibility with the repayment.

yes, thank you very much. I had another conversation with a financial service provider. Currently, I would actually want to go for a "simpler" model, consisting of:

20y fixed interest rate
20y KFW

After 20 years then a corresponding follow-up financing. It's not exactly what I initially had in mind, because of the risk of what happens if interest rates rise extremely, but if you repay properly and possibly make special repayments, then the risk is also lower, because interest rates can indeed rise somewhat without being more expensive compared to a building savings contract.

At some point it would of course become more expensive, but at the beginning you are more flexible.

But there are now probably many reasons why what I said is once again complete nonsense, right?

Edit: Repayment will probably be around 2% for our total amount, 3% would be too high a burden, especially in the first 10 years when there might be a loss of income due to offspring. Better to increase it significantly later and if you can before, then just make special repayments, then more is repaid.

In my opinion, the fear is rooted in the unpredictability and risk tolerance of the individuals.
Anyone who calculates a 30-year financing today will still have a considerable remaining debt after 15 or 20 years. And anyone who plans on a 30-year financing likely has little room to extend the term until retirement. This means a significantly higher installment to be paid with substantially increased interest rates.

And regarding inflation. Firstly, inflation also affects all additional costs and thus increases personal expenses, but it does not necessarily imply a corresponding increase in salary.