Is a TA loan sensible? Interest and loan offer are okay

Hello Jochen,
unfortunately I don’t quite understand your post and some details are missing or not clearly structured:

Interest rate for the TA loan: 0.85%, with an installment of €577.50 (€450 savings contribution, €127.50 interest), annual special repayment of €3600 (9x), term until allocation 9 years 9 months

So your bullet loan has an interest rate of 0.85% for a 10-year term which corresponds to a monthly interest payment of €127.50?
The savings contribution during the accumulation phase of the building savings contract is €450. What is the credit interest rate?
Does this "special repayment" flow into the building savings contract (if so, why not just €750 monthly savings rate) or into the loan (then presumably the building savings amount is also < €1800)?

Interest rate for the building savings contract: 2.15% (effective 2.44%), installment €921, term 9 years 9 months

Again, a jump in the installment here. Why? The repayment rate also seems strange to me (5.1‰?).
You should ask yourself regarding your installment what you can and want to afford. And then implement that.

Total payments including closing costs + annual fees: €206,939.74

What is the closing fee of the building savings contract?

The monthly installment averages €899.25 over the total term

The average installment doesn’t help you at all. Higher repayments are more sensible at the beginning than later (compound interest).

The building savings contract is very interesting in this case or do I have some fundamental misconception somewhere?

Here is a rough comparison (on an annual basis) in which I simply made a few assumptions:

[*]"Special repayment" is added to the monthly savings amount
[*]Closing fee 1%, account management fee €15 p.a.

Hello Jochen,

first of all, thank you very much for your effort. I will now try to present all the details as precisely/more precisely as possible in order to hopefully gain certainty about how good the offer is. The reason is that my main bank cannot compete with normal annuity loans at the top conditions, only the home savings contract is, in my opinion, competitive.

so your bullet loan has an interest rate of 0.85% for a term of 10 years, which corresponds to a monthly interest payment of 127.50 euros? The savings contribution during the accumulation phase of the home savings contract is 450 euros. How high is the credit interest? Does this "special repayment" go into the home savings contract (if so, why not just 750 euros monthly savings rate) or into the loan (then presumably the home savings amount is also < 1800 euros)?

Savings period until allocation:
€450 savings rate, €127.50 interest ((€180,000 * 0.0085)/12).
Credit interest 0.1%
Setup fee 1%
annual fee €12
Special repayment goes into the home savings contract, special repayment to remain a little more flexible and to not set the rate too high for unforeseen events (short-time work....... ) --> effectively €750 savings rate monthly
Allocation after 9 years and 9 months, with a credit balance of €83,502.43 (approx. 46%).

Home savings loan:
Amount €96,497.57 (special repayment in any amount possible once)
Nominal interest rate 2.15% (effective 2.44% as indicated)
monthly rate €921 (until allocation, however, a credit share of 50% is achieved through well-timed special repayments, the rate falls to €792).
Term 9 years 9 months

I hope this makes the offer a little clearer.
Looking at your calculation, the home savings contract is cheaper in terms of total costs, which also corresponds with my own calculations. In the end, I just want to know whether this offer is acceptable or competitive with an annuity loan with the same term.

"How much money do I have to pay in the period x for a sum of €180,000?"

Best regards Jochen