Bank does not accept own contribution

The property already exists, or does it also need to be financed?
In my opinion, your schedule cannot be met, even general contractors would have problems with that.

Is the plot already available, or does it also need to be financed?
In my opinion, your schedule is not feasible; even general contractors would have problems with that.

The plot is available, is almost fully developed, and was financed separately (without a land charge).

On my side, I am rather flexible with the schedule. Whether it takes 9 months or 18 does not matter much to us personally. Does the bank prefer to hear 18?

8,000 EUR for permits, surveying, and connections as well as 16,000 EUR for the architect are included in the house costs. The architect's costs are roughly estimated. More than just for the building application, because he should check several times, but less than if he takes over the entire construction.

Permits/surveying and connections 8,000 €? Where? I'm interested

- Surveyors cost 3,000-4,000 €
- Connections (water, sewage, electricity, possibly gas) cost around 8,000-12,000 € (for us it will be around 15,000 €, as we want to build about 15m in).
- Building application around 1,000 - 2,000 €
- Telecom connection I think around 2,000 €

Be sure of your costs, because if you need additional financing, it will get really expensive.

And again: The bank does not want to hear number X, but wants to see a plan.

If you want to take action right away, then go to an intermediary like Dr. Klein, Interhyp, or an independent broker and ask for your maximum loan amount, which bank might play along, and which documents you need.

Please report back

Separately financed means that a financing is running?

Schedule means the bank expects you to have drawn your loan within a certain period, if this does not happen you have to pay interest on the undrawn part.
In addition, you of course already pay interest on the drawn part.
Since the repayment of the loan usually only starts after the complete drawdown, every delay costs you real money.

Permits/surveying and connections €8,000? Where? I'm in

- Surveyors are €3,000-4,000
- Connections (water, sewage, electricity, possibly gas) cost around €8,000-12,000 (for us it will be around €15,000, since we want to build in about 15m).
- Building application around €1,000 - 2,000
- Telekom connection I think about €2,000

Be sure of your costs, because if you have to finance afterward, it gets really expensive.

Only about €750 remain open for electricity and around €3,000 for sewer work. I calculated €2,500 for the surveyor and €1,750 for the building application.