Sell the property completely or partial sale with investment?

The walls actually taper significantly towards the top. Where you want to go depends heavily on the starting situation. For me, this means the initial question: Is the existing structure usable or not? Don't forget: tearing it down alone costs 600 million. So you take a closer look at the walls.

Where you want to go strongly depends on the starting situation. For me, that means first the question: Is the existing stock usable or not?

Yes and no. Even usable stock should only be prepared for a concretely and currently marketable use, "more vacancy" is not needed anywhere.

Don't forget: the demolition alone costs 600 million.

But that does not necessarily mean that saved demolition costs could be counted as an asset position of the old building. It can be the cheapest option to speculate on a drop in demolition costs and only seek interim use.

Yes and no. Even a usable stock should only be prepared for a concrete, currently marketable use, "more vacancy" is needed nowhere.

The market situation at present is not bad. Apartments are rather scarce in the area. The big question is whether that will remain so for the next 20 years? But if one knew that, everyone or no one would do anything anymore.

It can be the cheapest option to speculate on a price drop in demolition costs and only look for an interim use.

Ha. We have had the interim solution for 30 years now. It also plays a role that the building has become an eyesore and people are ashamed of it. So it is not "only" about money.

The current market situation is not bad. Apartments are rather rare in the area.

There are huge differences between seemingly the same things, for example between the demand for an apartment from a tenant’s side and the same apartment from the side of an owner-occupier or a landlord (and among the latter again, between investors and those actually interested in the rental business). Also, no one simply asks for “1 piece apartment” of a certain size, but a fan of a concrete floor moves on to the next property when he sees marble. Inexperienced new investors regularly overestimate that supposedly lofts are sought in every big city.

And “market” in this sense is very localized: if the same penthouses three streets away have a nicer river view, it doesn’t help at all if the target property is sought on the citywide scale.

It also plays a role that the building has become an eyesore

That is rather a plus.

Let’s see when I get around to following up on your more detailed location info. The more concretely object-related one talks, the less one misses the mark. However, it only really makes sense when your relatives want to give you the “speaker mandate.” As long as your discussion here with the community and their discussion with “Mr. X” are only parallel, it doesn’t get you anywhere.

That's more of a plus point

Huh?

However, it really only makes sense if your relatives want to give you the "speaker mandate".

Sorry, I wouldn't bet on that. The matter isn't mine. I'm here to ask questions. Sometimes someone knows the answer, sometimes not.

Sometimes someone knows advice, sometimes not.

But you can only get good advice if you have all the information

I would also like to contribute, as such projects are my daily bread, but unfortunately that is not possible without concrete information.