Financing - which construction financing is sensible?

Hello,
I/ we are facing the same problem:
However, it should be said that my girlfriend can only work part-time. We are not married but the desire exists.
My thought is as follows:
Once the house is built, I would like to marry her and she would move in. We would split 1/2 (installment + expenses = "rent")
If she should have children and can no longer work, I would still credit her monthly rent share.

Example:

She pays 500 EUR monthly for 3 years (12*3*500) = 18,000
In the 4th year she has a child, (12*1*500) = 6,000
In the 5th year she goes back to work and again pays 500 EUR monthly = 6,000
= 30,000 EUR

Now we have the property value (according to bank valuation) of
105,000 EUR for the land
250,000 EUR house

= 355,000 EUR

Thus, after 5 years I would register her in the land register by way of donation, proportionally with 8.5%.

Since I bring in the land and am the one financing it, that was my first thought.
I don't want to disadvantage her, but also not prefer her. Before making any promises, it would be good to know whether this idea even works.

Is that even possible? Also with regard to the mortgage, etc.

Do you think I care that I will be paying off the house alone with €2000 monthly? My wife takes care of the children, the house,

Hello,
I/we are facing the same problem:
However, it must be said that my girlfriend can only work part-time. We are not married but the desire exists.
My thought is as follows:
If the house is built, I would like to marry her and she moves in. We split 1/2 (installment + expenses = "rent")
If she should have children and can no longer work, I would still credit her monthly rent share.

Example:

She pays 500 EUR monthly for 3 years (12*3*500) = 18,000
In the 4th year she has a child, (12*1*500) = 6,000
In the 5th year she goes back to work and pays 500 EUR monthly again = 6,000
= 30,000 EUR

Now we have the property value (according to bank valuation) of
105,000 EUR for the land
250,000 EUR house

= 355,000 EUR

Thus, after 5 years I would register her in the land register by way of gift, proportionally with 8.5 %.

Since I bring in the land and am the carrier of the financing, that was my first thought.
I don’t want to disadvantage her, but also not prefer her. Before I make any promises, it would be good to know whether this idea works at all.

Is that even possible? Also with regard to the mortgage, etc.

Thank you! I also want to be made aware of this. Of course, you have to think in scenarios. But not just assume the worst case. You have to talk about it, but for me, the discussion is too one-sided. My planned financing is not being discussed at all. Because the plan is the most likely scenario and that's why I would also like some advice on it.

Hello,
I/we are facing the same problem:
However, it should be said that my girlfriend can only work part-time. We are not married yet, but the desire exists.
My thought is as follows:
Once the house is built, I would like to marry her and she would move in. We split 1/2 (installment + expenses = "rent").
If she should have children and can no longer work, I would still credit her monthly rent share.

Example:

She pays 500 EUR monthly for 3 years (12*3*500) = 18,000
In the 4th year she has a child, (12*1*500) = 6,000
In the 5th year she goes back to work and pays 500 EUR monthly again = 6,000
= 30,000 EUR

Now we have the property value (according to bank appraisal) of
105,000 EUR for the plot of land
250,000 EUR for the house

= 355,000 EUR

Thus, after 5 years, I would register her in the land register by way of a gift, with an 8.5% share.

Since I bring in the land and am the financing guarantor, that was my first thought.
I don't want to disadvantage her, but also not prefer her. Before I make any promises, it would be good to know whether this idea actually works.

Is that even possible? Also with regard to the land charge, etc.