House construction, how much can we finance?

Is that the profit after taxes? Let's just assume that, then it's super simple: save for 3 years and comfortably build with well over 100k equity. Then the bank will also take this secondary occupation seriously. Until then, convince your girlfriend.

I mean, as of today, what good is a random figure of 20-50,000€ annually (why such a wide range??) if nothing remains in the private account - in other words, you can't and don't want to contribute anything from it?

Yes, the profit is after taxes.

The range is so wide because it is simply not really predictable what will remain. If I knew I earned 50,000€ every year from it, I would become self-employed.

At the moment, a lot of money has still flowed into the business.
Or how should a trade be built up without capital?

And since profits are made with the capital, the capital should not be permanently tied to anything.

And where is all the money of the heirs supposed to come from, if not from real estate (Germans are not a people of stocks & funds)? And who else is supposed to buy the overpriced heirlooms, if not other heirs?

Usually, the heir generation wants to improve themselves. A house with land is worth 300,000. It is sold and converted into equity. Add 50,000 of their own savings and they already have 350k equity to look for a nice new house. That one can then cost 700,000.

What you also forget – demography. With the baby boomers, the best-provided generation slowly retires and can relocate their center of life; moreover, they live their lives very differently from the frugal (pre-) & war generation. Example: a big motorhome with a sticker saying "We squander the inheritance of our children".. With the adequate care in old age, a big dreamt inheritance can turn out quite differently.

All statistics on inherited wealth in Germany speak against that. It increases year by year. And that also per inheritance case and not only overall. There are always individual cases with squandered inheritance or that everything goes to care for them.

Everything that comes after the baby boomers is numerically smaller, and significantly so. This can hardly be meaningfully compensated by immigration, especially not in the segment of high-priced single-family houses or semi-detached houses. Surely, there will still be large inheritances, but also significantly more houses will become "available" – and the generations mainly eligible as buyers (20-45 years old) no longer have the prerequisites as before. At least across the board.

The rate of homeowners is continuously rising. According to your theory, the increase should have noticeably flattened after the baby boomers were taken care of. It did not. The next generations have proportionally built more own homes. That the heir generation will very well have the prerequisites, I have already mentioned above. The heirs themselves often do not have well-paid enough jobs to afford their own home. You are right there. That was easier before. But that is easily compensated by the inheritance. You have no idea how "good" it feels when I bust my ass to do my master's degree alongside my job to move up further. To be able to afford a property by my own strength. And my neighbor puts his feet up, doesn’t lift a finger more than necessary at work, and proudly announces that he has now paid off his property. With dad’s advance inheritance. Now he is even thinking about buying a holiday home. The trend is towards second homes.

So there are definitely hard limits in this game – and no cycle runs forever. The perpetual motion machine does not exist for fundamental reasons.

That’s true. But no one can say when it will end. Or rather, all predictions about the end of the price rally have been wrong so far. The last was the prophecy that Corona would push prices down. After all, so many were afraid for their jobs and would not make big investments and commitments. Current figure: house prices rose by 2.9% in Q2. Within 3 months! Put another way: anyone who thought they would save some equity from April to June to later buy the 500,000 house would have already had to save 5,000 euros/month just to offset the increase in value.

It's not quite like that... as a side business.

It has been running for three years and, of course, had to be financed initially with private capital.
By now, it supports itself or rather nothing more is being transferred from the main income.

Since it involves trading in goods, a lot of capital is naturally required accordingly. I am liable as a sole proprietor, of course.

My girlfriend has already been living with me for three years. However, she thinks that building a house is too expensive and that she would have to expect many restrictions for decades.
I myself will not move into a rental because the monthly payments just disappear there and there is nothing left in old age.

But I think it should not be a question whether rental apartment or own home if it can be financed securely.
I know it from my parental home with the owner-occupied house. Her parents could never have afforded it financially. That is why there is a lot of respect there.

What can you calculate as an average area for an owner-occupied house? Can you manage with €100,000 within the city?
Ginseldorf, to stay with the example, would already be a bit too far away for me. You would also necessarily need a car again to do something in the city.

if you both are not pulling together then your income is too low (I assume the €4,500 is your combined income?).

The self-employment must run for at least 3 years for a bank to even consider it and possibly take it into account.

So a connection by train would be the absolute minimum. You want to go to the cinema, have a relaxed drink, and if I were dependent on the car, I might as well stay and build in the little village where I grew up. For example, I know building plots in the city forest. There, the square meter costs €210. Imagine an apartment for two children near Marburg. You pay at least €1000 without a garden. She doesn’t want to think about it yet, but if I build, then only as a couple. I at least want to inform myself and take further steps like consultation talks, etc. It doesn’t hurt to wait another 2-3 years; by then, you also have accumulated a large amount of equity.

I can understand her; she is still young and enjoying life! When you take on such a project along with the financial effort, both have to want it. Otherwise, soon we’ll have the next thread "Girlfriend breaks up with me during the building phase." One-sided goals create pressure and can have the opposite effect.

if you two are not pulling in the same direction then your income is too low (I assume the €4,500 is your combined income?). Self-employment must run for at least 3 years for a bank to even consider it and possibly take it into account.

The self-employment has been running for over three years. I am quite sure that when the time comes and she informs herself / gets advice on the topic, the direction will actually be clear. As already mentioned, I am not building alone. But she wants to leave the village here herself in the future and for that, she has to become active as well, otherwise nothing will happen.

So a connection by train would be the minimum. You want to go to the cinema, have a relaxed drink, and if I were dependent on the car, I might as well stay and build in the little village where I grew up.

I know, for example, building plots in the city forest. There, the square meter is 210€.

Then take a look along the train lines towards Kassel and Gießen (theoretically also towards Frankenberg and Erndtebrück, but the connections are much worse there), for example Cölbe, Bürgern, Kirchhain (which also has a bit to offer itself), etc. and in the other direction Niederweimar, Niederwalgern... all at least a bit cheaper than Marburg itself and with a decent train connection. It will probably be difficult enough to find a plot anyway, so go ahead and look, and if your girlfriend insists she doesn't want to, then you don't have to buy one.
May I ask where you grew up?