Financing after separation, what happens next?

Just write down your income and financing conditions. If you still have 20 years fixed at 1.2%, that is actually worth its weight in gold right now, as long as it is somehow manageable.

Beim Hausbauer wird vermutlich auch noch was fällig. ...

depending possibly on the EXACT terms in the contract?
AND the individual "negotiation skills"!

with a FIXED price and rising construction costs, some developers might even be grateful for a cancellation?

Maybe it depends on the EXACT conditions in the contract?
AND the individual "negotiation skills"!

With a FIXED PRICE and rising construction costs, some developers might even be grateful for a cancellation?

But it only works if you bluff and don’t let them see your cards.

Would also look here at what penalty payment would be required to get out of the contracts.

However, this should be done cleverly, best to get some advice. Possibly, in the current situation, one ends up breaking even.

with a FIXED PRICE and rising construction costs, some developers might even be grateful for a cancellation?

If the house is not finished for another year, most of the cost increase is probably already factored in. I wouldn’t have too high hopes there, besides, they also smell a rat when the customer comes with a cancellation.

Trying is better than studying, or something like that :)

In the current situation, it's better not to build than to finish sometime in 2023 and then be under sales pressure. You live separately, pay your rent and then still have to pay the bank for a house you don’t even want. Our neighbor has been trying to sell his house since January; back then, the offers weren’t high enough for him, now he would take them gladly.