1) Living room integration into main building cube and roof form
As is mentioned, the living room is indeed detached and its connection to other main spaces is week, specially the kitchen which is in a long distance for a family with two kids.
In this stage I suggest to shift the kitchen/dining box (keeping the same size) towards the living as the attached drawing (even more if possible considering the tree).
The design already includes an open dining and grill area in front of living room and the French windows let a very strong connection of Inside/Outside for the
kitchen/dining area with sufficient space under the tree for a table or bench.
2) Entrance area / stair case / wardrobe / guest toilet
As you are looking for a more open and welcoming alternative in addition to the concern over the cloggy wardrobe, I suggest separation of the guest toilet from the wardrobe.
This require the shift of the living room and pavement (keeping the same size) toward the south in order to leave a hallway (rather than the wardrobe) for the entry and preserving the connection of kitchen/dining and living room.
Though you like the idea of the guest toilets wall not going all the way to ceiling and in this separation you can preserve the idea, I highly recommend a sort of isolation of toilet from other parts through other methods such as change of material with less thickness at the high 50 cm in a way to keep the qualities you wish.
The chosen staircase is interesting, I just would like to suggest shifting the steps a bit (maybe only 2 steps) further inside so that the entry is less congested and also leaving a pausing point at the main door.
3) Cellar – wellness and storage area
Shifting the dining box towards the living room, has left enough space for the wellness area in basement to accommodate a sauna, treadmill, bed etc as attached. I also suggest opening of the toilet door to the other side.
Shifting the living room box towards the south, expands the light cell for the cellar and let the opening of another door and access way through the light cell towards the Haustechnik and storages if a separate access than the hobby room is intended.
I have not worked on your goal fourth. Nevertheless I decided to submit this, may it come to help.
Finally hope you enjoy your home of dreams!
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