How many KFW programs can be used?

Hello dear community,
my wife and I have signed for a semi-detached house and have already been to the bank.
The amount is safe, but we are asking ourselves which components we could still take...?

The fact is, the program "Energieeffizient Bauen" (Nr.153, €100,000 at 0.9%) since we will be building a KFW55 house?

Would the component "Wohneigentum" (Nr.124, €50,000 at 1.26%) also be possible?
Because then we would have basically €150,000 with the KFW at 0.9% and 1.26% respectively...
At the bank, we are at 2% until full repayment for the entire project, as we are doing it through the building society saver.

And would it even make sense to claim the KFW?

KfW loan definitely makes sense because there are repayment grants, so you basically don't have to repay the entire loan. This goes through your bank, which has to take that into account.

There is no subsidy for the 124. You have to see if it is interesting for you. There are conditions attached. For example, the first year is interest-only, then a total term of 10 years. It is then annoying if you have the rest over 25 years. You just have to calculate that, also with the interest rate for the remaining financing.

Check if the 124 makes sense. Basically, you also have to find a bank that offers both programs. The banks don't make much money from it and are not obligated to pass it on.

We had the Energy Efficient Renovation and the Home Ownership Program. The reason was the low interest rates for the former and especially the repayment-free initial years. The repayment grant was still quite low back then. For 60,000 Energy Efficient Renovation, there was only a 3,000 euro grant. But also 0.7% interest instead of 2.5% for a normal bank loan (2012). Also, the Renovation loan (no idea if that also applies to the Energy Efficient Construction loan) can be paid back in full at any time without prepayment penalties. We also did that after 5 years and terminated/redeemed both loans. The Home Ownership Program only had a 5-year fixed interest period. To my knowledge, the latter program can only be applied for once. I don't find the interest rates for it so great now. The argument would be the repayment-free period though. For us, it just fit well since all 3 components were concluded with a 5-year fixed interest rate. That was really great: on the one hand, we had super low interest rates when the remaining debt was largest, on the other hand, we could get out of the loans quickly and easily and could benefit from the halved interest rates again after 5 years.

Calculate for yourself whether the installments fit! It can happen that the installments are higher in total despite low interest rates than when forgoing a KfW loan.