Financing options for optimal support?

I consulted a bank regarding construction financing and was presented with the following structure:

1) KfW loan which is redeemed after 10 years (maximum fixed interest period). The remaining debt is transferred into a
2) Annuity loan with a 15-year fixed interest period (the bank does not offer more), which also runs alongside it
3) In the meantime, a home savings contract with Riester subsidy is funded, which will then redeem the annuity loan by the end of the fixed interest period. The remaining debt goes into the home savings loan.

The background is that, according to the bank salesperson, this way you capture the maximum state subsidy including child bonuses, and you also get a fixed interest rate there until the end of the term. Even with the costs of the home savings contract, you would still be in profit. I could possibly also include a pre-term there, but this has so far not been priced into the offer.

What do you think about such a construct, apart from the bank getting triple commissions?

So one really had to know exactly whether one is financing 60% of the costs or 80% of the costs or more.

If you are below 80% or less, it would then be more sensible to run it through an insurance (Allianz, AXA, etc.) as a construction loan with a long fixed interest period. They are currently very good there. You get 20-40 years fixed interest, constant rate, and you can plan everything well! Often the KFW loans still offer discounts, i.e. cheaper interest rates than normal.

Wohnriester?
Well, I don’t understand people who mix RETIREMENT PROVISION with HOUSE financing... that is a “good product” for the companies/sellers—they make money with it, what remains for the customer:
1) poor returns!
2) if you use the loan, it must be taxed at “retirement age” (deferred taxation) = no one really knows at what tax rate it will then be due! So even if today you got 0.10% or 0.20% cheaper rates this way, in the end you will pay for it!!!
But no advisor tells you that... they only want to make money with you.

If you want to do “Riester” to get the subsidy, then it only makes sense if:
1) you invest in investment funds, where returns are still higher than inflation
2) you choose a “net tariff,” without high acquisition and distribution costs (in the fine print, normal Riester contracts sometimes list these at up to 8% for these costs, which eats even more of the return!)
3) you should be able to select the funds yourself where the money is invested, so you can, for example, choose a good one (with reasonable returns) and also low-cost ones!
Because that way you have 20-30% more assets after 20-30 years in your retirement provision (calculated with the same RETURN!) than if you leave it to your bank advisor.
So folks, it’s about a lot of money, better spend 1-2 days thoroughly dealing with it, and in the end have 20,000-30,000 EUR more!!!

PS. If you are above 80% (sometimes it can already be 70%), it could of course make sense to take the bank with 10-15 years fixed interest and then do the rest with a home savings contract. To have no interest rate risk at all. But you have to calculate everything very precisely.
And please, normal home savings contracts are there to get the favorable interest rates later, that’s what they’re for!!!

The KFW is only a guarantor bank. The KFW loan itself is processed by your financing bank. Once the fixed interest period of the KFW loan is reached, to my knowledge, the prolongation is not done by KFW but by the financing bank. However, this is not "transferred" into the existing annuity loan but continued as an independent prolongation.