City villa 180 sqm without basement + double garage

However, I am a layperson in house construction and architecture.

Precisely for that reason, in my opinion, you should not let yourself be seduced by software skills, especially not to start at the professional level you are used to. A house design process is especially multi-stage for professionals: even with several decades of professional experience, an architect will never start a design with the input plans, but will always stay on the preliminary design level as long as all rooms do not have their final dimensions. With software, you have to "imagine" that you are still working with a soft pencil at the beginning.

I myself had such a "play area" on the gallery as a child, so for me it’s not just a hallway to look down from,

Yes, I had that too. Galleries are nice. But they also carry a lot of noise upwards. I’m not sure if the combo gallery next to the bedroom is so great. When the kids get older and claim your gallery, then say goodbye to peace whenever you want to sleep, and the kids have their clique visiting, because the gallery is perfect for chilling on the sofa. It’s the same with toddlers’ sleep: some can do it, others can’t. So you have to weigh everything up and/or consider, for example, a door that not only separates but also breaks the tube effect.

A ceiling would separate the windows.

An air hole has no ceiling.

Our neighbor is building next to us at the same height and the view for us would be onto a house wall after about 10 meters. At the same time, they can look in on us too much.

That’s why gardens, bushes, and hedges were invented. Ten meters is also very generous.

Shading is definitely planned. It is the absolute south side.

That should also be considered in relation to the gallery plus sleeping floor.

Pantry will be covered. Without it, there would be more tall cabinets (where the door to the pantry is).

Just halve it towards the outer wall and create a cloakroom.

How to use the space under the spiral staircase meaningfully?

Or here: if turned the other way, you could actually run the cloakroom under the stairs. We, for example, have it that way.

You have a good eye that we planned it the other way around.

We’re in a house-building forum here.. something like that comes in handy

Question for the group: How to use the space under the spiral staircase sensibly?

[*]Coat rack
[*]Dog bed
[*]A suitable sculpture
[*]Coat rack in front - movable and a safe behind it
[*]Coat rack in front and movable and bulky everyday items behind it, e.g. a stroller
[*]No coat rack in front and as a highlight a terrarium or aquarium
[*]Wine rack and humidor
[*]...

[*]Display case with Rolex collection

However, I would never "hide" frequently needed items like a stroller behind a cabinet/shelf that I first have to move out of the way. Items that are rarely needed (perhaps winter/summer clothes) rather yes.

Otherwise, I agree with the aquarium.

I like galleries and open spaces - we have those too.

However, we also have three cats and not two children. That works. Otherwise, it is really very loud.
At first for the kids, when they are supposed to sleep but you are watching the AoKrimi, and later for you when you have teenagers who turn night into day but you need your sleep.

Therefore, I find such an open concept rather unsuitable for everyday family life.
Or you have such a big house that you plan the open area for everyone and can still separate the sleeping area with a door and thus soundproof it.
Here you could also separate the gallery area with an additional wall with a door and equip the wall to the bedroom with special sound insulation. If it absolutely has to be open upwards. I would probably rather decide on a closed version upwards here. If needed, the room created above can be left open and used as a reading corner, a second office, a play area for small children, etc., or even turned into another room (but I would rather choose the open version for that). Also as a second TV area certainly an advantage. Then Dad can watch Bundesliga downstairs with his buddies and the kids can watch Kika upstairs (and not annoy the Bundesliga watchers *g*) or you have guests, sit together comfortably and the kids don’t annoy ("I’m so boooored"), but watch Arielle from Amazon Prime together with the visiting kids upstairs and downstairs you sit comfortably with a glass (or several) of wine and in the background there is NOT Arielle.