Floor plan of a new single-family house, 1.5 stories, 148 m²

Right, thanks, I will include that as well.

You could certainly think about it again, only 1 child is planned anyway, so the 2nd room upstairs could also be used as a guest room, that could only change if suddenly there are 2 children. I also think that a larger sofa bed in the living room for guests could be enough, or your solution with the pull-out bed in the children's room.

Where one is planned (it was no different for us), a second one often follows. Biology can be cruel sometimes. But that means you have a guest room available for the first few years. After that, you have to see. There are plenty of solutions. For that, though, I wouldn’t “block up” my house. Plan for yourselves how you find it ideal, and then see at the end if a nice guest corner can be integrated through the smallest changes. I would also ignore the bedroom on the ground floor for now. If it comes to the point where you really can’t manage the stairs anymore, then you also can’t manage the house. If it fits, fine, but don’t get creative with it.

That's true, on one side they are not planned very deep, the question is, do you need a window in the walk-in closet? Or maybe the window could be made smaller. The longer side should definitely have at least 60-70cm deep cabinets, the other side probably only needs 40cm ones for small items. [/QUOTE]

If you have open cabinets, you will eventually cover/darken the window anyway because of the colors/fading. Mold shouldn't be an issue if you have ventilation.

I think using the study as a future bedroom is rather unlikely. Those are still your cabinets and the storage room upstairs, you would have to go there at least occasionally. Also, you've stored cleaning supplies, ladder, ironing board, etc. in the study for decades because the utility room is so small. Where should all that go now? A stair lift would probably be the better solution. If one of you is really bedridden/has walking difficulties, a bed in the living room would probably be okay for you until then.

If you combine the study and utility room, you will also have space for supplies, ironing, etc. The space will fill up quickly.

And if you really will only have one child, it would be a shame for the unused room upstairs.

Okay thanks for the notes, then I will discuss it again and I think she will agree that a later bedroom downstairs is not necessarily required. The problem then is that the PC/desk still has to go somewhere in case of another home office. So downstairs a small office after all or reduce the children's rooms again and have another room upstairs? Or will it be too tight upstairs then? How big should the utility room be in your opinion? 10m²? If I could be sure that there will only be one child then it would all be a bit easier. But as Evolith already said, biology is a tricky thing and we both have some family history when it comes to twins.

The size of the utility room also depends on what you want to do there. Just for laundry or also storage, housework, etc.; you should question your own needs. In general, the hallway seems clearly too large to me, considering the allocation of other spaces, and could, for example, give the small room 2-3 sqm more so it would really be a "room" or also serve as a small pantry. You could then possibly partition this in lightweight construction and use or open it again as needed without major interventions. Above all, you should enter the actual measurements of the furniture, including to see if the windows are positioned correctly. A child’s room over 17 sqm doesn’t have to be, it won’t be nicer in there just because it’s bigger.... Maybe something also needs to happen in the ground floor with the stairs/entrance so that the hallway doesn’t waste so much space.

The toilet arrangement works for us like that.

But the toilet must at least have its front edge on the 2-meter line. So it would have to be rotated and then without a privacy screen.

What the hallway has too much of is missing somewhere else. Please read the pinned posts. My neighbor has a single bungalow with about 6 sqm of utility room, where at most a shelf for batteries and roasters and three cans fits. Dryer on top of the washing machine... I don't see laundry space for a family there.

The problem then is that the PC/desk still has to go somewhere if there is occasional home office again. So downstairs a small study or shrink the children's rooms again and have another room upstairs? Or will it be too tight upstairs then?

I would suggest a different house concept. Which plot is it supposed to be on your site plan?