Multi-family house without spouse involvement - ownership question

I would only like to recommend making a prenuptial agreement regarding the actual question.

But I have a few questions for you.
How do you build 4 residential units for 250 k?
How is that supposed to work with the floor area ratio and plot ratio?
How many parking spaces are required in the respective development area?

Please both(!) go together(!) to a lawyer and get advice. You can regulate just about everything in a prenuptial agreement. There are certainly situations in which it makes sense for one spouse to carry the entrepreneurial risk while the other “secures” the assets, for example by owning their own property.

This can (and should) then be balanced out in a prenuptial agreement for the hopefully unlikely event of a separation.

See it as an opportunity to protect your assets from claims by banks, etc.

What do you all want now with a prenuptial agreement? The OP wants precisely that his project = becomes a joint project.

My wish would be that this project runs in both our names.

The situation has two components. One legal and one emotional. The legal one is to be clarified soberly: who pays, who is listed in the land register, who is involved in the financing, and what happens in case of a separation (=marriage contract)?

The emotional one must be answered individually. Is it automatically a joint project if _one_ spouse builds a house? Is it a joint project if both invest time in the construction? Is it also a joint project if one invests time and the other supports from behind the scenes? All this can of course also be considered in a marriage contract.

Therefore, the reference to the marriage contract, or to consulting a [RA], is already appropriate. And often they can also give a stimulus for thought regarding the emotional component…

What do you all want now with a marriage contract? The OP actually wants his project = a joint project.

I can’t understand that either... where is the problem? I wouldn’t regulate anything there at all... That the woman doesn’t want to have anything to do with it... what does she expect? That you bury the money until she’s no longer here? That you give it away? Refuse? Such a saying “I don’t want to have anything to do with it” is somehow completely twisted as a spouse. Let’s assume it’s a solid 10,000€, then one would say “it’s your money. Spend it on yourself.” But like that?

No. Your house, your loan.

... the loan is paid off anyway from the joint gains, i.e. monthly salaries – or are you starting now with separate accounts? That wouldn’t be unusual, but if you take your money only for the multi-family house, rent income then only into the rent income account, which she doesn’t want... somehow that’s a little bit of a combative and separation message from your wife, isn’t it? o_O And you want to bring her on board – because of the management? Responsibility? Or the costs? I find it all more understandable if a woman wants to be brought on board, but the heir wants to organize everything for himself first. Things happen ...

Just read the opening post.

There is a discrepancy between:

1. His wife doesn't want to have anything to do with it and he asks if he is alone in the land register, so that the matter is settled.

2. He wants it to belong to both of them preferably.

Therefore my question on page 1 is what the OP actually wants.