Desire for joint property - currently separated

I always say with these thoughts about the worst case (which, by the way, also make me feel uncomfortable): "I neither know my future self nor yours. We have to protect each other from these people." That the depths of today's self often reveal themselves in such situations is an unpleasant but desirable side effect. From my point of view, a possibly painful but necessary exercise before "binding oneself forever." And yes, all concepts that arise from this, whether a sophisticated marriage contract with exclusions here and there or pooling everything together and trusting our future selves, have their legitimacy as long as both partners do not feel coerced and feel treated fairly (or both feel unfairly treated to the same extent).

yep, nothing to add to that!

On this occasion, a perhaps fitting quote comes to mind; at first, I didn’t remember from whom, but quick googling helps:

A compromise is perfect when everyone is dissatisfied.

Or also:

A compromise is only just, useful, and lasting if both parties are equally dissatisfied with it.

However, I personally believe that the goal in such a partnership should be to find a consensus. Then everyone would be equally satisfied.

In this spirit: A peaceful weekend!

I always say with these thoughts about the worst case (which, by the way, I also don’t feel comfortable with): "I don’t know my own future self nor yours. We have to protect each other from those people."
That the depths of today’s self often reveal themselves in such situations is an unpleasant but desirable side effect.
From my point of view, this is a possibly painful but necessary exercise before "committing oneself forever." And yes, all concepts that arise from this—whether a sophisticated marriage contract with exclusions here and there, or throwing everything together with the trust in our future selves—have their legitimacy as long as both partners do not feel coerced and are treated fairly (or are both unfairly treated to the same extent).

That is good. In our partnership, we also rely on being close enough so that our "future selves" do not develop independently of the partner. In an authentic partnership where openness and closeness are lived, personalities usually do not develop uncontrollably and arbitrarily in any (negative) direction. If it ultimately should be so, then either the partner’s personality was misjudged from the start, or the closeness was not as pronounced as thought, or one-sided. These scenarios, of course, occur relatively often in practice, as can be seen from divorce rates. But it makes the complex problem of "future and relationship" somewhat more tangible.
Honestly, I firmly believe that 90% of marriages fail not due to a lack of compatibility but because of a deficit in communication skills. When I then read considerations here about who lived rent-free at whose expense for how long, and other "keeping score against each other," a red warning light always goes off for me.

Especially in the case of separation, which often involves the hurt of at least one partner, often of both mutually, one will discover completely different sides of the (formerly) loved person. To think about this possible situation beforehand and to develop an arrangement when the relationship is in calm waters is as responsible as it can be.

It was his house, inherited from his mother, which he already brought into the relationship (however, his ex-wife and their daughter still lived in the house, which is why we rented). In fact, it was never an option for him to put me on the title deed, that is correct.

I understand, nevertheless it would have been possible/necessary to clearly close the "old life" (ex-wife) and, of course, to start something completely new with you, for example in a new/different house and without this old story. As already described, I myself don’t like half measures, because in your place I would not have been able to feel equal in the house and therefore do not understand your partner. It probably was not due to financial reasons, but rather the partner’s lack of willingness, who strictly rejected this shared ownership. This constellation, where he decides where to live and also how (alone on the title deed), gives me stomach aches; I think one could have anticipated and found other solutions, but stubbornness is hard to deal with.

When I read such considerations here about who has lived rent-free at whose expense for how long, and other "offsetting against each other," a red warning light always goes on for me.

....I absolutely understand that, although I don't like this constantly demeaning "offsetting," with which one puts another person in a dirty corner while standing oneself in the white, radiant area. That is simply too simplistic for me. But the warning lights should also go on when couples don't want to talk about it at all or don't like to because it hurts their romantic ideas. I would absolutely recommend to my children and children-in-law to talk about it, precisely so as not to eventually realize that they started from something different. What is wrong with talking about it, and why is it so ugly labeled as "offsetting," "businesslike"? After all, you also take the better tax class as a married person. Is it also businesslike when you capitalize on love?

Especially in the case of separation, which often involves the injury of at least one partner, often of course mutually, you will discover very different sides of the (formerly) loved person.

...and unfortunately, by far often other sides of ourselves as well....

To think about this possible situation beforehand and to work out an arrangement when the relationship is in calm waters is as responsible as it can be.

Exactly—and in a foresighted way so that afterwards no one has to feel treated badly, and no one even has the chance to put the other in such a position if people, views, or lives change. That should be the goal in my opinion, and I like the fitting saying: "Always address the 'bad' things right at the beginning."