Is financing a single-family house feasible? Start house construction end of 2023

A 30m2 apartment is neither here nor there. It might be okay for Grandma at first, but later it will hardly be rentable. Anyone who depends on such an apartment will not be able to pay high rent. Therefore, you will make a loss and additionally have tenants in your house. So if I were you, I wouldn’t calculate higher rental income here.

You should also calculate whether the setup still works with children and 20 or 40 hours. With 30 / 40 hours, you need good and reliable childcare and even then it is stressful. You really have to want that.

Where I get stuck: 2 x home office means 2 offices. Are the 140 sqm accurate? With a technology/utility room and 2 children's rooms, it could already become a bit tight…

I would also skip the granny flat. It doesn’t make financial sense. Otherwise, a case of if not you, then who. However, I would recalculate everything with reduced incomes (one at 80-100%, one at 50%).

KfW loan: €153,000

[*]Effective annual interest rate: 1.84% [*]Installment: €493.47 [*]Repayment rate: 2.612% [*]Fixed interest period 10 years, total term 30 years

Thanks for the hint! Of course, it's €253,000 KfW loan for two residential units, not €153,000.

In my opinion, the installment does not match the amount of €253,000. It should rather be close to €900.

Regarding 253,000 euros, in my opinion the rate does not fit the information. It should rather be around 900 euros.

Correct, it should be 938.63€. Something is not right.

One more thing about the [Einliegerwohnung]. With that income and renting to relatives, the tax office will cover it. You just have to keep all costs separate from the beginning. When grandma is dead, it's easy to rent it out to students, weekend commuters, etc.