Transfer property according to share

hm, yes. just out of interest: if the property is bought during the marriage with money that was already available / brought into the marriage beforehand: does the property then count as marital gain? I'm not really familiar with this, which is why I never really consider a prenuptial agreement...

The property may be an increase in assets (maybe), but the assets brought into the marriage are not. It is irrelevant whether the money still exists as cash, as property, or in crude oil.

But the OP's problem is not with the property, but as correctly recognized, with matrimonial law....

Which marital property regime was agreed upon? Only then does it make sense to discuss the rest.

Because under the statutory marital property regime, at the end it is split half and half. 1/3 more or less.... 1/2

Thank you for the answers.

Currently, before the marriage, it is the case that as the landowner, I am also the owner of everything built on it. And that is, after all, also equity from my girlfriend.

This can be implemented relatively easily by transferring her shares of the land to the extent of her equity.

The question now is how it behaves in case of a separation:

- Worst case: After one year, a finished house stands on the land (land charge registered) and her proportional share of the land no longer corresponds to her equity. Then I would have a problem.

- If we leave it as it is, she "feels" like she is paying for a house that she does not own because it is on my land.

I am looking for a fair solution that also counts her years as a mother as "repayment years." Is this solved via the land or does it require a marriage contract?

You are the owner, but that does not mean that the accrued gains do not have to be compensated in the event of a possible separation. Again, if you want to disadvantage your wife compared to the statutory provisions, you need a marriage contract, the land register, etc. do not matter.

What do you mean by disadvantaged? In the event of a possible separation, the house is on my property and her equity (existing before the marriage) is invested in it. I alone decide what happens to this property. It is precisely here that I want to give her rights. I am not sure if the legal requirements here are sufficient.

First of all, I would have said that the money still has to be paid back, regardless of whether it is in the form of a piece of land or otherwise. Since German law has a few pitfalls (e.g. the question of whether they haven't already given you their money as a gift), I would have drawn up a contract for that.

The day before yesterday, a notary (possibly somewhat self-interested?) told me that various court rulings tend to no longer recognize intra-marital loan agreements (which would have been my first choice of contract).
Although I can hardly imagine that, in your case I would probably pay for a few hours with a specialized lawyer or notary to get solid advice on the legal possibilities (you have to see the notary anyway regarding the land transfer); then it might become clearer to you what you need to arrange, what you don't, and how you want to allocate things.