Financing evaluation. Specify total equity to the bank?

We are borrowing the money for the house and not for speculation

I already understood that, but it amounts to the same thing. You take out a loan so you don't have to sell the stocks.

If it stays at 5%, you did everything right. If it drops by 50% and the follow-up interest rate is 6%, then you did it extremely wrong.

For me, there is nothing against a 100k reserve, but you are speculating with over 300k. That's a whole different ballgame.

For the bank, you bring enough equity into the financing. Up to 40% equity, the financing interest rate would have become even cheaper for us; after that, the bank wouldn't have cared about more equity since there is no risk anyway.

by selling shares/portfolios at the current peak and exchanging them for concrete, in my opinion, you would have securely realized the existing profit, speculating and betting everything on black can go so wrong, you also don't have a crystal ball. But although, the chance of profit is indeed infinite and the loss is limited to 100%.

It does not necessarily have to be securely resolved at a specific moment. To me, this does not sound like speculation, but rather like a long-term investment, which in most cases leads to a reasonable return over time. The money and income are available. I also wouldn’t touch the portfolio and take a 4% loss to save 1% interest. Possibly use the maximum special repayment in the first 3 years to further reduce the financing interest costs.

And you want to build a frugal 400m² with 400€ with a fairly moderate 150m² house

So 3100 EUR/m² is not exactly moderate, even if it is not huge in terms of size. The main question would be how you arrive at the potential value of 800 K. If it is lower (e.g., only 600 K), the risk increases. I would probably pay a little more than just the land + incidental costs in cash.

So you can already see, it simply depends on personal risk tolerance. You have to decide for yourselves.

Hi,
I would invest all the equity (minus a buffer of about 50,000) in the house purchase.
With your income, it will be paid off in no time.
I would keep and rent out the condominium.
Once it's paid off, you will have enough capital at your disposal and can still buy stocks or whatever you want.
No matter what happens, you won't have any housing costs anymore, plus you'll have the rent from the condo.
Regards, Olli