Floor plan optimization city villa + fill consideration

How about the following layout: a large nice bathroom upstairs for everyone. As long as the children are small, they will go to the bathroom with you anyway, right? Instead of a children's bathroom, better to have the washing machine upstairs, saving you from carrying clothes up and down the stairs. In return, make the bathroom downstairs bigger/with a shower. When the children are older and want their own bathroom, they can use the one downstairs. Many people plan their house like this.

If you have 4.35, then it's 4.40m shell construction?

Yes, almost, it is 4.38m shell construction. Whether it is ultimately only 4.34m, I have not measured.

Yes, the problem with the bathroom downstairs is, I think, the laziness to carry clothes down. My parents had a bathroom upstairs and one downstairs. The one downstairs was not used by anyone. You have to get dressed more in the morning in case you meet someone and take clothes with you. That wouldn’t work. It would have been better if my parents had two bathrooms upstairs. It’s also annoying to go down the stairs extra, at least I think so.

We are afraid of water damage with the washing machine upstairs. We think if something should happen, it is better in the utility room downstairs.

I will write more about the windows once we have reconsidered them.

Budget: Yes, we have one. It shouldn’t get much more expensive.

Yes, almost, it's 4.38m rough construction. Whether it is ultimately only 4.34m I haven't measured.

Ok, you have to reckon about 5 cm loss. Where is your sofa located?

Actually, you don't really need an extraordinary floor plan, you have "standard" requirements (don't get me wrong), if I haven't overlooked anything. Have you ever looked at the floor plans of the major house providers? Just Google for example "Viebrockhaus Maxime 710 II". Upstairs there is only one bathroom, but it is large and there is an additional storage room (possibly usable as a children's bathroom?). On the ground floor there is also an office included, but you can rearrange the rooms a bit for a larger bathroom, bigger wardrobe, pantry...

We are afraid of water damage having the washing machine upstairs.

How likely is water damage? Is it so much less serious downstairs? Doesn't household insurance cover that anyway? In tens of thousands of apartments, the washing machine is not in the basement... The (probably very small) probability of water damage wouldn't be worth the daily laundry carrying for me.