Purchase-demolition-new construction process + timeline feasible?

How exactly does the land charge work for the financing?

The land charge serves to secure the loan and is registered for the same amount.
So you need a land charge of €520,000 for the bank that provides this loan.

[*]Demolition – ~October
[*]Arrange financing as soon as the building plan is approved and signed - ~October

You can also arrange the financing earlier. Depending on your mood.
Can you pay all the costs by then? The demolition will not be cheap either.

Theoretically, the bank could also say: "You have destroyed the value of the old house, so we only recognize the land costs and thus not €230,000 but €100,000."

That will not only happen theoretically, but actually. Because you don’t have any value there except the land. So you would have thrown €130,000 out the window.

I find "thrown out the window" a harsh expression. There are no other building plots/houses, so that was our only option. :D Yes, we will also pay for the demolition in cash. How exactly could we arrange the financing already now? The advisor from Dr. Klein said that a bank will only do that once we have the finished building plan with approval.

In summary, we had thought that we have a total sum of 750 k€. Of that, we paid 230 k€ in cash for the house/land, 30 k€ will be added in cash for the demolition, and the rest will be financed. Theoretically, thanks to the early inheritance, we could also contribute more as equity, but we actually do not want to.

I find "thrown out the window" harshly phrased. There are no other building plots/houses anyway, so that was our only option. :D

Unfortunately, that is often the case. But actually, the money is simply "gone" and will never come back. You just have to know that. Nothing more, nothing less.

How exactly could we arrange the financing already? The advisor from Dr. Klein said that a bank only does that once we have the finished building plan with approval.

Most banks want to see a plan from you. Plan = calculation from the architect, quote from a general contractor, or similar. It must be clear what is being built and what it is supposed to cost. The approval can also be a disbursement condition, for example.
The advisor was talking nonsense. Otherwise, it really gets difficult if you can’t pay for the plot from equity ;-)

Ok, got it, thanks!
Then we'll wait a few days, our general contractor wanted to get in touch with a new draft.
What put me off was the long process of transferring the land register to us and the demolition companies, who say there’s still a bit of time until October, but if we can only proceed once we have actually been registered in the land register, it could still be tight timing-wise.
Let's hope... :/

There they mentioned December 2021 as a possible start of construction driven by high capacity utilization, which would be absolutely fine for us.

Snow, icy cold, frozen ground, etc... building in winter is a bad idea. Depending on force majeure due to the weather, etc., realistically it will only start in spring. So don’t have too high expectations for December.

We would have the €230k registered as a land charge/equity capital for the financing of the remaining €520k. Is that possible even despite the demolition of the old house? Theoretically, the bank could also say: “You have destroyed the value of the old house, so we only recognize the land costs and therefore not €230k but only €100k.”

The amount of the land charge is the same as the loan amount you want to get from the bank. If I understand you correctly, you want to finance the full €520k, then of course there is a €520k land charge.

You don’t get the money paid out as a lump sum, but money is only given after construction progress and you can only spend the money on the construction. Pragmatically speaking, the loan is secured by what you build plus the value of the land. Therefore, it does not matter that you demolish the old house.

Ok, great. Thank you very much for the answers! Basically, as I said, we are not really under time pressure, whether it starts in December or March does not matter much to us. Our architect also mentioned that they only build up to a maximum of 5°C, or carry out certain construction steps exactly because of the risk of frost.

Regarding the loan, you understood it correctly. Our original plan was: We have a total amount of €750k and invest about €230k + demolition as equity, and the rest is financed. However, because there was so much time between the old house purchase and the start of the new construction, the Dr. Klein advisor said that the easiest thing would be for us to pay the old house + demolition in cash, have it recorded by the bank as "already paid equity from the total amount," and finance the entire rest from the bank, so that we would be back to our original assumption. Simply so that the bank doesn’t say "you are financing 100%" for the conditions, but sees that we have already invested our entire equity for the total amount.