Building a house with a granny flat financially realistic?

Even death itself. Disrespectful

It's not about the death of the parents at all? And if the parents want to live in the house with their child and grandchild because they like to spend time with the grandchild, how exactly is that taking advantage?

In the past, multiple generations living in one house was common. That's great. It wouldn't be for me, envy strikes, but you want to build your home. All good! Don't count on or think about the inheritance, which isn't one. You don't count on someone else's money unless it is already your own. Rental income must be declared for tax purposes, which does not always have advantages.

Thank you ignored HilfeHilfe. Exactly. My parents would love to spend every second with our daughter. We are absolute family people and I would never even think of having my parents finance the house and then dump the child and dog on them. It's a shame that was understood that way by HilfeHilfe. But well. As ypg already says, people used to live in one house. We get along very well and that's why we decided that. And actually, I just wanted information about financing, etc. Exactly, ypg. You can't count on other people's money. We don't even know how things will turn out. That's why we want to plan without it. @Matthew - thanks for the info. I didn't know that

We are currently building 140 sqm plus a granny flat of 50 sqm as an extension. Without land, kitchen, furniture, etc., our total cost amounts to about 450k. The additional costs for the granny flat will be around 125k. Regarding construction method, equipment, etc., we could certainly have chosen something cheaper and we are not contributing much in terms of own labor, on the other hand, construction costs have increased further ... so it can only be compared to a limited extent but maybe you can get some orientation from it anyway. Even if we rented out at local market prices, the granny flat will never generate a profit. But we also built the granny flat for family reasons.

Mathematically simply not feasible, the income is too low, there is no equity. Existing stock is the only viable way in the current situation.

I already mentioned the taxes in the first answer.

Ok, you are now calculating the rent, but actually you have to pay for the granny flat and taxes from it.