Financing offer single-family house including building savings, experiences

Update:
All interest rates stated as nominal interest rates.
All bank interest rate commitments 10 years.

Offer 1
Equity capital: €24,000
Muscle mortgage: €20,000
Bank total €255,000, 3.55%, theoretically finished after 29 years, installment €1,179
KfW 124 total: €100,000, 35 years, 3.41%, installment €414
KfW 297 total €100,000, 35 years 2.76%, installment €378
Mixed interest rate: 3.35%
Total installment: €1,972
(Bank is not interested in proof of own work)

Offer 2
Equity capital: €24,000
Muscle mortgage: €20,000
Bank total €255,000, 3.55%, theoretically finished after 29 years, installment €1,179
KfW 124 total: €100,000, 25 years 3.38%, installment €507
KfW 297 total €100,000, 25 years 2.68%, installment €471
Mixed interest rate: 3.32%
Total installment: €2,160
(Bank is not interested in proof of own work)

Offer 3
Equity capital: €24,000
Muscle mortgage: €20,000
Bank total €255,000, 3.23%, theoretically finished after 30 years, installment €1,111
KfW 124 total: €100,000, 25 years 3.38%, installment €507
KfW 297 total €100,000, 25 years 2.68%, installment €471
Mixed interest rate: 3.14%
Total installment: €2,090

Offer 4
Equity capital: €20,000
Muscle mortgage: €20,000
Bank total €355,000, 3.28%, theoretically finished after 31 years, installment €1,562
KfW 297 total €100,000, 35 years 2.76% installment €378
Mixed interest rate: 3.24%
Total installment: €1,940

Offer 5
Equity capital: €39,000
Muscle mortgage: €20,000
Bank total €336,000, 2.96%, theoretically finished after 32 years, installment €1,389
KfW 297 total €100,000, 35 years 2.76% installment €378
Mixed interest rate: 2.98%
Total installment: €1,767

Offer 6
Equity capital: €39,000
Muscle mortgage: €20,000
Bank total €336,000, 3.24%, theoretically finished after 31 years, installment €1,467
KfW 297 total €100,000, 35 years 2.76% installment €378
Mixed interest rate: 3.20%
Total installment: €1,845

With the original building savings offer, the entire term was secured, but I feel better about the offers without building savings. You have to take the interest rate that is current in 10 years, but by then some of the amount will have been paid off, and I expect that we will also have saved a larger sum on the side by then.

My advisor recommends option 1 or 2, because the bank there is not interested in proof of own work and is generally more relaxed. However, the interest rate is worse there, and I think we can provide proof of own work for this amount. I will get more information about this from our general contractor today.

€39,000 equity capital is probably too much for us, which is why I am not inclined toward these offers. If you reduce the down payment here, the interest rate gets worse.
I am currently tending towards offer 3. Possibly adjusted slightly, e.g. €5,000-€10,000 more equity capital, which would bring the installment closer to €2,000. Or increase one of the two KfW portions to 35 years, which would probably reduce the installment by about €100. But I think I can currently live with about 3.20% nominal interest rate.

What does Muskelhypothek mean? That already sounds like self-deception:

In any case, this is not money that someone lends you with interest, but simply your own work. In other words: trades included in the purchase price are not carried out by the general contractor, but are taken out of that and you have to do them yourself.

Which ones are they supposed to be? Has this been coordinated with the general contractor?

How do you want to save €20,000 with that? Certainly not on materials, but on labor costs. Roughly calculated: if the general contractor charges €100 per hour, €20,000 equals 200 hours of work. If the amateur takes twice as long as the professional, you have to provide 400 hours of work on the construction site – in addition to your own working hours.

How do you imagine that?

Which ones are those supposed to be? Has that been coordinated with the general contractor?

Those are usually the common finishing tasks: laying the floor, painting, landscaping, possibly screwing the toilet to the wall. What many people do, because turnkey usually means that especially floors/painting are not done by the general contractor. Turnkey building is not the same as ready to move in.

It's chaos here at the moment. We've had quite a bit of bad luck. Short version, since we had to postpone our financing until after Christmas for various reasons, we're unfortunately taking the interest rate increases and have gone from a 3.02% mixed rate to presumably 3.51%-3.6%. It hurts a lot, but what can you do. The installment will probably be around €2100. Main portion over 30 years, €100k KfW 297 over 25 years, and €100k KfW 124 over 35 years. KfW is increasing the interest rate on the 124 tomorrow and we'll probably have to accept that, since it was submitted but will only be processed tomorrow.

KfW will increase the interest rate of the 124 tomorrow and we probably have to accept that, since it was submitted but will only be processed tomorrow.

Then I hope that by submitted you meant the submission to the KfW. Although once submitted, the application is actually approved within seconds because the "processing" is done automatically by the system. No human "processes" the application.

That does hurt a lot, but what can you do.

Yep, it has basically gotten more expensive every day. Meanwhile, it is actually about 0.30% higher for 10 years.

We have informed the bank about the BZA from the KfW, but they will only process the entire application tomorrow and according to our financial advisor, unfortunately, we will also have to share the KfW increase. I just saw that both KfW programs have also been increased. Our house project is really an incredible streak of bad luck.