Multi-generational house with underground garage for 3 families

If there is so much money in the account that such a 1 million project can be paid for...

Why even waste a thought then and not everyone build for themselves? And maybe one takes the parents with them...

Or the parents pay everything or the majority?

The risk behind this, if something happens... would be clearly too big for me...

As interesting as I find that money doesn’t matter to you, the thread creation is pointless with the information you provided. There simply are no contents to discuss, i.e., either you provide more relevant info or the thread will be dead after another 5 posts.

The previously mentioned objection regarding expanding, such as acquiring another property, was also discussed at length. However, we all share the same opinion here, namely that we are too closely connected to this corner and unfortunately, at the moment, it is like winning the lottery if someone sells here in this corner.

I would currently be interested to know whether, in your assessment, it is realistic to realize such a building on a property with the mentioned dimensions. I will gladly provide more detailed information about the property tomorrow.

Best regards

such a plot of land with the specified dimensions is realistic

Not only measurements matter
It is not even known here whether there is a slope, where the road is, or the orientation.... 20 meters can be very little.

... and one of the most essential questions: are 3 residential units allowed on the property? Even if there is probably no development plan, this question should perhaps be fundamentally clarified. Is there possibly a parking space requirement after all?

Otherwise, I am of the opinion that 1000 sqm would basically be sufficient, but as ypg already wrote, 20x50m can be great, but can also be difficult to divide considering driveway, neighbors, slope, etc. So a site plan with the neighboring buildings marked and a few measurements would be good.

Attached is the current plan. It is number 10!