Increase repayment or top up building savings?

Under the current conditions, I would personally clearly increase the repayment. If you start now with repaying 3%, a good portion of the remaining debt will be paid off in the next 7 years and you can watch the whole situation a bit more relaxed at the moment.

Definitely towards repayment.

Please explain why? Do I have an advantage if I reach the building savings contract earlier with 40%, or does it hardly make a difference?

The crucial point is that you save money from now on with an increased repayment

Please explain why? Do I have an advantage if I reach the building savings contract earlier with 40% or does it hardly make a difference?

You have to calculate (or have someone calculate) the structure.

Monthly rate €883, interest rate 2.25%, repayment 2% over 15 years, expires by 2032 at the latest.
Outstanding debt at the end of the fixed interest period €184,000

With these numbers, I come to an outstanding debt of €161,000.

And if the outstanding debt should actually be correct, then the repayment and/or interest rate do not match.

You have to calculate (or have someone calculate) the construction.

With these numbers, I come to a residual debt of €161,000.

And if the residual debt should be correct, then repayment and/or interest rate are wrong.

No, the residual debt is correct, I must have looked incorrectly.

OK, just as I thought. Better to put it into the repayment. But I will have to take a closer look at how the interest on the building savings contract is.