Paying "rent" to the partner... how?

Um. I earn more than he does (only 500€, so I say we earn similarly, but it’s not like he supports me financially, I didn’t want to leave it like that).
He obviously has family backing, meaning substantial equity and guarantees.
Since my student loans still exceed my building savings contract, savings accounts, and portfolios, and there will be no inheritance/gifts/support etc., it’s understandable and okay for me that he buys alone. But, as I said, that shouldn’t be the issue.

And yes, if necessary, he can also move into the property alone, why not? There’s no do-or-die situation. The only question is how much there is to eat, meaning how much I pay.

Yes , things always turn out differently than you think, which is why I run through the scenarios. It’s just that here I’m constantly accused of living in a shared usage community where I’m just waiting for it to fall apart.

Why don’t you throw everything together and build together? It doesn’t matter that he brings more as long as you grow old together, for the rest there are regulations

Equity is higher
Household income is higher
2nd debtor present

He has family support, meaning substantial equity and collateral.

I understand. But then I don't understand it: I am exactly where is in the post before mine. Together you achieve more than alone and each on their own. That's often how it is with division.

...or you pay the installment until his equity is balanced, and after that you continue together. Everything is possible!

If he can of course build without [FK], then the idea is obviously not feasible.

At the latest with the house construction or at the signing or wedding, there is only one account.
This, which I would call the "German" model with separate accounts always [..], is just unnecessary stress.

Seriously? No own account anymore? 2020?

I would have said that I then cover living expenses and possibly additional costs and he pays the loan

The problem here is: He is paying off his house, you save 500€/month in addition to rent. But in proportion, that is less than what he gains with the house. Because you save cash, some of it is often gladly spent on furniture and so on. So you end up with less for your old age than he does. And that is not the goal when you care deeply for each other. On top of that, you probably have to endure your mother-in-law with annoying remarks. Whether you pay rent or not. None of this is ideal ops: