Floor plan design and placement - Single-family house approximately 200 sqm on a 900 sqm plot

We are planning a built-in cupboard / built-in wardrobe on the wall to the right of the entrance door.

Rather not, because your bathroom is wider. If you put the downpipe to the right in the corner, it will come out in the office next to the window. You have to draw it yourself - I can’t compare the dimensions on a phone. Do you understand the problem? If the architect comes up with the idea of corners or loops, i.e. an S-bend (I don’t even know if that’s allowed), then as the client I would definitely reject it.

Ah ok, I understand. I thought maybe the pipe could just start somewhere in the floor of the bathroom, but it probably has to start at a wall of the bathroom, and there really aren’t walls in the ground floor that would be suitable and placed like the bathroom walls upstairs. With the background, I can now ask more targeted questions as well. Thank you very much!

Children's bathroom: What bothers you about it? That you potentially hear noise from showering in the children's room? Or something else? I basically don't think it's a bad idea to rather move the shower into the utility room. We do not want a shower with a glass partition. WC on the ground floor: The size is due to the fact that we want to keep the possibility open to retrofit a shower. As long as this is not the case, a large cleaning cupboard should go in there. You can still reconsider the door... You would then place it right next to the basement stairs? So that there is maximum cupboard space towards the garage?

This corner in the 2nd children's room I just don't like. As the saying goes, you can piss on a good layout in the snow ;-). I would therefore try to keep the children's room wall straight. The children's rooms are also big enough that there does not necessarily have to be 60 cm of space for the cupboard behind the door, i.e., you could possibly still play with the wall/door to the children’s bathroom/utility room here (or make the utility room accessible from the bathroom). Yes, the door right next to the stairs. I would also have the shower in the ground floor bathroom built right away. Only the fitting and the drain, no partition. You can always put a cupboard in front of it, but later it will be a bigger renovation (new tiles, new pipes). And how often does one retile, maybe after 40 years? P.S.: Where is a cupboard actually supposed to go in the dressing room? There are only windows ...

So I don't like it 100% yet, but as a suggestion for the upper floor ...

So 100% I don't like it yet, but as a suggestion for the OG ... [ATTACH alt="Bild1.jpg"]62860[/ATTACH]

That's how I would see it too. However, I would also like to mention that a dressing room should also have space for a stool (better 2) and a mirror. Ok, the mirror could be well placed on the opposite wall in Romeo's example. I don't have the orientations in mind, but I would try swapping the children's rooms with the parents' area: master bathroom above the guest toilet, bedroom top left of the plan, children's bathroom to the right of the stairs… that would also work better with the drainpipe.

However, I would also like to mention that a dressing room should also have space for a stool (better 2) and a mirror.

Otherwise, it's just a walk-in closet
:D