Quick Check of Construction Financing Conditions

Why don't you go back to the bank that offered you the 1.8% for 15 years? Now that you - wherever you got it from - have the 50k equity, this interest rate could even become a bit cheaper.

Yes, I had spoken with them. This comes from a calculation of own contributions, since we have own contributions amounting to the purchase incidental costs, which makes it appear financeable, but it is not. Thus, 1.88% over 15 years would now be possible for the remaining amount, so like the comparison above, 1.91% over 15 or 2.33% over 20 years. I am currently wavering between the two scenarios.

Approximately 50,000 own contribution? You have set yourselves quite a task. With the own contribution only the labor is planned (materials still have to be purchased). Even if we assume an hourly wage of 25 euros:

50,000 : 25 = 2,000 man-power hours

Respect!!!

Where did I say that? Maybe I explained it wrong. Our own contribution is 15k. That would have been enough at Sparda to fully finance the rest. But that's no longer an option since there is only a 15-year fixed interest period. We probably want 20 years and are currently leaning towards the 2.33%.

Have you already analyzed the financing amounts exactly and checked if everything is really included? Somehow, this all seems a bit confusing to me. If I had to guess now, you have a total sum of €370,000, of which you want to finance €332,000. Additionally, you have €15,000 as personal contribution and roughly €20,000 as equity. Is that roughly correct?

If yes, then you have...
...definitely 100% financing
...a small house or a very cheap plot of land to make the €370,000 work
...probably calculated the incidental building costs quite narrowly

Regarding the financing:
You have surely already calculated what remaining amounts remain after the fixed interest period. If not, there are plenty of calculators for that. In my opinion, it is also crucial how much you repay. If you repay 4%, you will be finished after 20 years and I would take a 15-year fixed interest period due to the low remaining debt. At 3% (which is probably the most common rate), it is difficult because there is still 50% remaining debt. On the other hand, lower interest rates can significantly accelerate repayment. Under 3% repayment it is even more difficult. Short fixed interest periods (here 15 years) lead to a high remaining debt and thus to a corresponding risk at refinancing. However, in your situation, the interest payments are then almost as high as the repayment and the loan becomes very expensive. In addition, there is still a considerable remaining debt after 20 years.

Can you provide a few more details so that your situation can be better assessed? Ultimately, you have to decide yourself anyway, but based on the information provided, one can currently only say: If you want more security, take 20 years; if you want a cheaper loan, take 15 years.

Total sum including personal contribution is 510k, 15k personal contribution, leaving 495k to be paid. 50k equity, that is 10%, means 90% financing needed, namely 445k. 100k is KFW, leaving 345k as a large loan with the question of whether 15 years with lower interest or 20 with more. However, we also assume that we can make special repayments, but do not plan to, meaning it should also be reasonable if absolutely no special repayments are made.