Purchase opportunity for an old building from 1953, assistance with evaluation

Here is a quick sketch regarding a possible renovation. In orange are the structural changes that the current owner has already made and that we would also leave as they are, and in green are things we spontaneously thought of.

The second picture is supposed to represent the upper floor. Unfortunately, there is no floor plan for this. We have considered converting the stairs to the attic into a pull-out staircase so that the hallway is not so narrow. Where the dashed line is, there used to be a wall that was demolished. You can still find two different floor heights there, which means something would need to be changed. Also so that the children's rooms are more nicely arranged. It would also be possible to put the removed wall back in and then create a playroom in the third room.

To me, it looks like the property is what you actually want, not the house. And honestly: I understand that, because the floor plan is extremely impractical, convoluted, and uses the available space where it doesn’t add any value...

The total living area is 140 sqm, of which the practice occupies 40 sqm.

New construction is off the table; here we pay between 200,000 (steep slope combined with slippery ground) and 350,000 (still a slope but not as bad) for a plot of land, and the plots are only between 500 and 750 sqm in size.

With the existing building we now have in prospect, we could even pursue our hobby of archery due to the large plot. The plot is already leveled, and the retaining wall is also in place (however, it belongs to the city and thus does not burden our wallet).
A new build would never be cheaper. We have already discussed this with a prefabricated house company and a timber construction company.

The only alternative would be to give up the house space if it is not affordable for us or hope for an alternative should house prices actually fall further.

Then I recommend negotiating the house down to 250k and tearing it down. And then build new on it or you look again for a somewhat younger house in your area. Because otherwise you sink 300-400k into an old existing house that needs to be completely remodeled and will never be worth that much again in a few years.

So, I don't think a new building would be better there. From the photos, I don't see a real conservatory, at least as I interpret it. Although I always equate a conservatory with glass walls.

However, I don't understand the concept of the floor plan. What is the huge entrance area on the ground floor supposed to be? And how do you want to divide it? And why tear down an existing staircase to the attic? I would urgently take proper measurements of the upper floor. And also give the ground floor plan some measurements.

Ground floor concept .. maybe also reconsider including the parents' area on the ground floor ... Where is a useful terrace?

I think with the floor plan you can definitely get something out of it with a bit of creativity. I would, for example, move the kitchen further forward so you don’t have to carry the groceries through the whole house. You had written that you want to do a lot on your own? Then you have quite a big project ahead of you for the next few years. Ultimately, I would see it like this.... you can sink a lot of money if you do EVERYTHING from scratch or you think about practical solutions. That would be, for example, suspending the ceilings and connecting that with new wiring. The ceiling height allows for that.

In the floor plan, the windows of the conservatory are not drawn because there was only a balcony there at that time. However, these are not glass walls but simply many windows. The owner called it a conservatory, and we adopted the term. We really like the kitchen in that position because it leads outside to the terrace, making the path very short. Where else should you put the kitchen without completely changing the room concept (costs)? Currently, the entrance is at the back of the house when you come from the street side, which is completely illogical by today's standards. Therefore, we wanted to move the entrance area to the front and design an entrance there with many plants, thereby extending the gardening season. Also, a small table with chairs in case you have visitors with whom you want to chat briefly but not go directly into the living room.

Yes, we know that it is a project over several years, but we are always tinkering in our free time anyway, and the only pressure to move in is the one we put on ourselves since we are basically living rent-free at our parents' house in a currently sufficiently large apartment.

The idea of lowering the ceiling sounds interesting. I will write that down and then discuss it with an architect if it comes to that. The renovation wouldn't start before 2024.

By the way, negotiating down is not possible because otherwise the owner would stay living there and not sell. He originally wanted €350,000.