New single-family house construction in 2025 possible on a low budget?

I see the financial structure as not feasible as long as the apartment is kept. When the apartment is gone, I see it as feasible. And Karsten has nicely demonstrated that the apartment as an investment is nonsense. Now it is a matter of deciding whether to move into a home of one’s own or stay with the family and hold on to the emotional value of the apartment. In the end, that is something the OP must decide for themselves with their partner; I would want to move into a home of my own.

Town & Country earlier and today are hard to compare, as about 1 year ago many things were incorporated into the standard, but the price is now correspondingly higher. And some costs can be saved with careful planning; the excavation of 30cm for the slab can usually be distributed on the property.
In BW, however, you cannot choose not to install photovoltaics; that definitely has to be included in the calculation.

Basically, I also see more the sale of the apartment here and a correspondingly lower loan. 4% tax-free and guaranteed savings are simply hard to beat.

Hello everyone,

I have a short update,

Everything happened very quickly. After we viewed the existing house on Tuesday, we expressed our interest on Wednesday, got an appointment with the financing advisor on Thursday afternoon, subsequently made an offer over the phone, and received approval today.
The realtor did a great job as an intermediary. We are really happy.
The payment will be around €1,800. We will first move into the ground floor and rent out the attic (about €750 cold). Tax-wise, operating at a deficit makes the payment quite acceptable. The average nominal interest rate is preliminarily at 3.97%, I think we will still make slight adjustments.

85% of your payment is pure interest. You'll never be done that way.

Where does this assumption come from? Of course, the total interest payments are correspondingly high, that is reality. We manage 2% initial repayment, and are mathematically done after just under 27 years. By the way, I will then be 56 years old...

Just a quick note, this is about the existing house that I briefly mentioned in the first post, not about the more expensive fictitious new building project.

I'm happy for you. Have fun in the new house.