Is house construction only possible with funding from KfW and the Landesbank?

Hello,
We are 36 and 41 years old, have 2 children (2 and 5 years old), and own a plot of land in RLP.

Our net household income is about 4000 euros (+500 euros child benefit).

We generally ask whether it would be possible to build solely using funding and equity? For example, a new build with a granny flat (cold rent 500 euros) for 500,000 euros.

Possible funding for this would be:
KfW 124: 100,000 €
KfW 298: 100,000 €
KfW 300: 170,000 €
ISB (Mainz): 175,000 €
Equity: 25,000 €

Thus a total of 575,000 € possible.

Now the question is how does a bank benefit from this calculation? This would all be done through KfW loans and basically no direct bank loan, right? Is the bank obliged to do this? The bank is interested in issuing its own loans and earning interest. I hope you know what I mean. Or is the bank only necessary for processing/submitting for KfW?

Last question, is building a house with 4000 net income + 500 euros cold rent (assumption 65m2 * 7.75 €/m2) manageable at all? I always read about at least 5-6k net household income.

Thank you very much.

Hello, We are 36 and 41 years old, have 2 children (2 and 5 years old) and own a plot of land in RLP. Our net household income is about 4000 euros (+500 euros child benefit). We are generally wondering if it would be possible to build solely through funding + equity? Example new build with a granny flat (cold rent 500 euros) for 500,000 euros. Possible funding would be: KfW 124: 100,000 € KfW 298: 100,000 € KfW 300: 170,000 € ISB (Mainz): 175,000 € Equity: 25,000 € Thus a total of 575,000 € possible. Now the question is how does a bank benefit from this calculation? Since the whole thing would run via KfW loans and practically no direct bank loan, right? Is the bank obliged to do this? The bank is interested in granting its own loans and earning interest. I hope you know what I mean. Or is the bank only necessary for forwarding/submitting for KfW? Last question: Is building a house with 4000 net + 500 euros cold rent (assumption 65m2 * 7.75 €/m2) even feasible? I always read about at least 5-6k net household income. Thank you very much.

To make it short: KFW298 and KFW300 are not combinable! Also, I would doubt that a bank would participate here without granting a share of the loan themselves.

298 for the apartment insert and 300 for the house.
Should be combinable though.

And how high would the amount from the bank need to be for them to cooperate?
Thank you

298 for the mezzanine apartment and 300 for the house.
But it should be combinable.

And how high would the amount from the bank need to be for them to go along with it?
Thanks

Ah, ok. I understand! That slipped my mind.
Does the ISB have any guidelines regarding the combination of funding?

I can't say exactly what the bank requires. It might make sense, however, to simply waive the KFW124/298 portion and handle this volume directly with the bank, since the terms don't differ significantly from the current market conditions anyway. Compared to KFW124, you will probably get even better conditions on the open market.

Some banks already do that. We finalized our financing in March through Interhyp with a regional savings bank. It consists only of KfW and NRW.Bank loans. Brokers like Interhyp or Dr. Klein could surely help to mediate with a bank that offers such a construct.

Some banks already do that. We finalized our financing in March through Interhyp with a regional Sparkasse. This consists only of KfW and NRW.Bank loans. Brokers like Interhyp or Dr. Klein could certainly help arrange for a bank that offers such a structure.

May I ask how the financing looked for this? How did you search/filter this with Interhyp or Dr. Klein?