Single-family house (2 floors + residential basement + developed attic) approximately 200 sqm - changes

Site plan will be included sometime. Unfortunately, I cannot add it in the first post. Neighbor house/living space: I am not a lawyer. I am also currently having difficulty clarifying this legally, since we want to build a house first. The matter is probably quite clear: there are unauthorized openings in the firewall. No matter where we build an extension, we will not get permission to create living space. The process must therefore be: ask the neighbor to close the openings (probably measure the boundaries precisely beforehand and we will probably have to share the costs equally). If he is not willing to do so, it must be clarified legally. However, the matter SEEMS to be legally quite clear but lengthy. Once the openings are closed, we can do whatever we want with the house. Possibly we will make a guesthouse with 3 guest apartments. Until then, everything must proceed without major changes because it is not allowed without permission. So only securing, insulating, etc.

Reasons for the demolition
- no maintenance costs
- no insurance
- no sealed surface for rainwater etc.

so far it is just storage space without use
and costs repeatedly

The rear building is from 1903 and has some very charming details. Maintenance should mainly focus on the roof, as I can and want to do quite a bit myself in the coming years (after the house is occupied) (it's basically a hobby). Insurance and sealed surface area do not compensate for the 150sqm of storage space for us. There is electricity and water available there. So it is definitely usable. We really like the option of possibly expanding it someday.

I would still like to come back to the current ground floor plan draft. There have been no comments on it yet. Is it because it is even worse than the last one? Is it conceivable to shift this staircase about 1-2 steps upwards in the plan on each floor? Always upwards at the bottom of the plan: Basement: Starting double-winder then straight and at the top the exit winder again Ground floor: Starting about 1.5 times winder (up to the bathroom door) and then straight Attic: Starting 0.5-1 times winder and then straight up to the center of the house

I still want to come back to the current ground floor plan draft. There have been no comments on it yet. Because it is even worse than the last one?

It only makes sense if all floors are visible. Please also mark parking spaces for the cars so that the walking paths are visible. What about the area in front of the existing building? It looks like it is paved. Can that be removed and incorporated into the garden? Possibly make the house 2m longer for that?

I will only manage all floors tonight. Unfortunately, my program will not be able to properly display the stairs. The rooms on the dg and attic will basically remain the same, only the bedroom will get access from the hallway, become a bit larger, but the built-in wardrobe will be removed. On the attic, a bathroom with a shower will be added in line with the stairs. Regarding the property: yes, it is concreted and can/should be cleared again. Currently, there is a driveway there. This will probably stay there for now (house expansion takes priority). The car, which is only used once every two weeks anyway, will therefore be parked in front of the back house. Whether a parking space will be created in front of the house as part of the construction is still open. At most, a parking space is planned at some point. For us, the question about the bicycles is more pressing. They are used every day. So they have to be quickly accessible and still secured. Maybe a bicycle ramp to the basement =)