Grandma's house | Right of residence | Rent by oneself

So, financing the house at 100% of the loan value means that you will receive almost no money. From the bank's perspective, the value of the house is going down the drain. Why? The right of residence must be appraised; no one would want to buy the house without being able to live in it or receive rent.
==> €1,000 rent * 12 = €12,000 p.a. * 12 years remaining life expectancy = €120,000 value of the right of residence (simplified). This means the house should have a loan value under €100,000 for the bank, and you want to finance more than double that? Never, sorry.
Gifts yes, buying no. The heritable building right is also complicating. Short term.

I also don’t understand why you should buy it?

Heirs with registered right of residence are gladly accepted, I would stay away from everything else.

You are 31 and your grandmother 68? I would say intergenerational ambitious family planning.

With all due respect, but the idea is just stupid. If grandma wants to do something nice for you, she should simply give you the house and register a right of residence for herself. Then at least after 10 years you can be sure that the house can no longer be leveraged. If you also want to give her some compensation, you pay the ground rent for her and visit her regularly.

Bending over backwards for 20 years so grandma can splurge or eventually inherit your own money again makes absolutely no sense. Especially since the time horizon plays a significant role. You are 31, and even if you might not have that on your radar right now, maybe in 5-8 years you will be a married father of two children needing your own home. But you can neither finance another one with the mountain of debt, nor can you benefit your grandma with it...

That's exactly how I see it. How many heirs are there anyway? A gift plus registered right of residence or possibly usufruct would be fine. Then you could, as already mentioned, pay the ground rent and that’s it. Otherwise, you'll exhaust yourself financially now, the money will be missing for your family planning, and you'll stay stuck renting for many years because it’s the only way. When grandma dies in 20 years, you might not even have a need anymore—you'll be paying maintenance, the loan, and have to accommodate tenants.

As flattering as you may feel about your grandpa’s wish, please also think about your life planning. Of course, grandma could also pass away in 5 years, especially when you have a wedding and child coming up—but I would never want or have to “hope” for something like that :(

The 50 years of ground lease are also a sword of Damocles. Right? That means your possible future children won’t be living in the house anyway, if things go badly.

Right of residence plus leasehold? I wouldn’t do that. Those are two negative points that banks, buyers, etc. don’t like. Just wait and see, and you don’t have to exclude a future partner now, where it’s not even starting to get interesting. Don’t take it literally, but give it some thought. Everything will work out. You’re under no pressure. And she’s not an old lady either, the 68-year-old you have to save financially now :)

you are 31 and a senior employee with 2,100 net, you want to buy the house from grandma and make your life worse so that you eventually get the house.

I see no benefit at all, unless you can buy it for 50k with a value of 200k. Everything else is nonsense