KFW 300 Funding - Attractiveness

Well, the U-value of windows is just significantly higher than that of walls. Unfortunately, full glazing is not possible there.

Yes, but the discussion was about "floor-to-ceiling" (meaning from floor to ceiling lintel), not fully glazed.

Strictly speaking, you are of course right, although floor-to-ceiling without very large areas is hardly likely to occur…

Is it correct that after the fixed interest period expires, I have a special termination right, and that one can also choose a longer contract term?

Is it correct that I have a special right of termination after the fixed interest period expires?

No, at the end of a fixed interest period you always have a regular right of termination. You have a special right of termination with longer fixed interest periods. Namely, 10 years after full disbursement with a notice period of six months.

Thus, at best after 10.5 years. In practice, due to the successive disbursement of the loan according to construction progress, however, (considerably) later. If the loan, for example, is fully disbursed only nine months after the contract signing, you can terminate after 10 years and nine months with a notice period of then six months.

This is stated in §489 of the Building Code.

No, at the end of an interest rate lock period you always have a regular right of termination. You have a special right of termination with longer fixed interest periods. Specifically, 10 years after full disbursement with a notice period of six months.

Thus, at best after 10.5 years. In practice, due to the successive disbursement of the loan according to construction progress, however, (significantly) later. For example, if the loan is not fully disbursed until nine months after the contract is signed, you can terminate after 10 years and nine months with a notice period of then six months.

This is stated in §489 of the Building Code.

Thanks for the clear explanation. Now the only question is whether to gamble and choose a 10-year fixed interest period...

Thank you for the understandable explanation. Now the only question is whether to gamble and choose a 10-year fixed interest rate...

This is not just simple gambling. This is also mathematics. Take a 100k loan fixed for 20 years with a 30-year term. Next to it, you take a 100k loan fixed for 10 years with the same rate as for the first loan (which will then have a shorter term). After 10 years, you will then have a (significantly) lower remaining debt due to the higher repayment. You can then calculate how much the interest rate must rise so that you break even in the still remaining term (20 years) compared to the long-term loan. Maybe it will turn out that in 10 years the interest rate can rise to 7% and you still do not have to pay more. The 7% would already be very unlikely and therefore the decision quite simple. Actually, with the 10-year fixed interest rate currently (depending on years without repayment) you can repay almost 20% more in the 10 years than with the 20-year fixed interest rate (in the above example). That is already a sum and becomes clearly noticeable in a follow-up financing. (You should calculate it, maybe the sum is even higher if you move into a shorter term and thus even lower interest rates through the higher repayment).