Buy a condominium with a partner

So you mean there is nothing against it? We have saved up the equity in about 2 years... we are unsure whether the 10% equity is enough (the bank thinks so, but for our peace of mind that’s the question).

I wouldn’t have a problem with that. Why?
Renting for that size also easily costs at least €1,000 cold (new build) = €1,200 warm.
Installment + additional costs for the apartment are around €1,500 (that already includes 3.3% repayment!), then there remain €2,500 for living expenses. So only slightly more expensive than rent, but with a forced savings rate (repayment) of €11K per month included. The 0.9% interest on a €340K loan is €255 monthly – that is your “cold rent.” Would you get a comparable apartment rented for that?
And if you really have to move out in a few years (whether you then build a house or go bankrupt), in my opinion it is rather unlikely that you will come out at a significant loss – 3 years of repayment means you have already covered the additional costs at the same sale price. And even if you make a loss, so what? That’s how it is, but you have lived exactly as you wanted for several years. That would not be a reason for me to avoid the hypothetical risk (because it could also be different, that you experience strong appreciation). I also dare to cross the street, even though hypothetically I could be run over.

I love the ambiguous headlines. Others want to buy an [ETW] with a balcony.

To the point: If the money is not lying around, you actually have no hurry to buy something for your own use. Saving up is great and then see what comes, and then immediately go for a size that fits a little longer. If you really feel like it, just do it, because somehow it works out.

From which money will you then pay for the kitchen, additional purchase costs (approx. €24k), etc.? Or did I overlook that?

*glaskugel raushol*
the commercial vehicle factory on the other side of the Rhine is coughing and it seems to be turning into a proper flu.
If you are attached to it, I would take it easy for now.

You can do that, but with more than one child the place becomes too tight.
Selling early could end in a loss-making deal, as a lot of money is sunk into ancillary purchase costs and prepayment penalties. Are you sure you can and want to live there for at least 10 years?

What cold rent could be charged for the apartment?

Prepayment penalties do not apply to us because we finance through our employer and these do not apply to employees. Furthermore, we can finance at real conditions, i.e., about 0.8-0.9% over 10 years.

With what money will you then pay for the kitchen, ancillary purchase costs (approx. €24k), etc.? Or did I overlook that?

Loan contract is €365,000
I will pay for the kitchen and furniture out of my own pocket; until move-in, a considerable amount of salary plus bonuses will still be added for the kitchen.

so I would buy it. You can assume that in a few years the prices will have increased further.

so if you want to start with "Nachwuchs" in 7-8 years and then want to buy something bigger, you will have to invest more, but the further price increases in the coming years can be cushioned by the appreciation of this [ETW].

therefore: clear purchase.

PS. with 4,000 EUR net income and 365,000 EUR financing amount, everything is still within a "healthy" range.