Disagreements regarding construction financing

I can already give you the answer in advance:
Since the 10-year loan is "subsidized" and thus the 50K € from the KFW 124 would otherwise be allocated to the 12-year loan, an interest advantage arises when using the 124.
However, this does not change the fact that this construction is complete nonsense.

I briefly ran through the whole thing for a 100% financing at Dr. Klein. The interest difference between 10 years and 12 years is actually relatively large. Between 12 and 15 years, it is in the second decimal place, however.
It looks different for 80% or 85% financings. There, the interest rate shifts closer to the interest rate of the 10-year loan.

Thank you .

To me, it somehow looks more like they are looking out for the best interests of the broker/real estate company rather than acting in the customer's interest. I find just a 10/12-year fixed interest rate on the loan amount without any security very questionable.

I would inform myself independently of this broker and separately from the KfW loan next year. If the conditions with the KfW are good next year, you can still tell the bank that you need 50,000 euros less from them and would prefer to get it from the KfW. That is definitely better than the other way around.

No sorry, the 12 years are standard from the bank, the 10 years are the subsidized ones from the house provider.

Something just occurred to me: Have you asked the bank if the cooperation with the prefab house manufacturer might end at the end of the year? This could possibly be the reason for their urging.

I rather think that it should be completed as quickly as possible before the customer changes their mind somewhere. Construction companies and financial advisors work very closely together. If the customer has not yet secured financing, the contract with the BC is also not finalized. If the customer now has the stupid idea of looking at another BC in the meantime and possibly signing there, the financial advisor also loses their customer. (they can't score with quality anyway) They are both focused on the customer signing now and not in a few months.

The other question is, if you plan to start in August, it also depends on the house provider. Some house providers currently have very long waiting times, sometimes > 12 months.