Floor plan, not a specific single-family house, approximately 200m² with 2 apartments

Since I myself do enjoy the topic and am capable in the 3D area,

You probably mean "in the 3 sqm area," because your drawing is so gigantic – and thus practically unviewable for mobile device users. I took the liberty of shrinking it. can this please be configured so that such gigapixel uploads are prevented here?

Personally: Even as someone who can't really create sensible floor plans themselves, I immediately see too many corners and edges here, none of which really fit. On top of that, supposedly "clever features" were added, which simply don't work in this form. e.g. the children's bathroom feels like it was added afterwards, it wasn't originally there, and then it sounded like a really great idea. But building two doors into a <2sqm bathroom and having the downpipes run right through the living room is already very far from a functional plan.

Better think again about a room program (what is must-have, what is optional) and how you want to live in it, then go to an architect and/or look at existing plans to see if they fit you. I myself also don't have the ability to create a sensible floor plan out of nothing, but the good thing is, I don't have to ;)

Thanks in advance for the reply, the first one that doesn’t just seem like pure "destruction" to me :)

Keep in mind that usually rough dimensions are planned. A 1m wide toilet room already gets quite tight once you have to deduct something from that.

Regarding the more precise placement of the walls, I am still flexible in some areas. If 50+ mm more space is needed, that would be possible. The 1m width is measured from the inside of the wall, and the toilet room is only meant for the bare essentials. However, it would also be no problem to make the room a bit longer or wider. But as I already wrote before, I am also unsure whether that makes sense or not.

About the kitchen: look at where light currently comes into the room. I also have the feeling our terraced house kitchen could be brighter and less cramped. Don’t you cook much?

There is a large window on the exterior wall of the kitchen (size is flexible), and there is still the large opening to the dining room measuring 1.8x2m. If the door is ever closed, frosted glass is planned here so that light can still come through. But we do cook quite often, usually (completely) alone though. It’s not intended to cook with friends or anything like that. And if I look at apartments with a cooking island in the middle, there is usually only about 1.4m of space between.

Have you ever looked into sliding doors somewhere? Proper sliding doors usually need about the same amount of space on the side because that’s where the door slides into. Alternatively, you have folding doors. It’s just a question whether that’s really that nice and practical where you are planning everything now. The sliding door seems to me like your cure-all for flexibility and just "tight corners." I would put a question mark on that.

Yes, I have looked at sliding doors, among others from Knauf with the Pocket Kit. The sliding door disappears into the wall here and therefore doesn’t get in the way.

I don’t quite understand exactly how you imagine the bedroom at the moment. Sliding door running between two single beds and when you feel like cuddling, you leave it open and push the beds together? Or am I misunderstanding the idea? I think practically there will be a standard anyway, either you always have them open or always closed if you basically prefer a separate sleeping situation. Personally, I would plan a regular shared bedroom and put a pull-out sofa or similar as an alternative option in one of the offices.

No, it is a single wide bed. The door (with cutout) also runs into the wall and is basically an L lying down, so that the bottom edge of the door would barely pass over the mattress. Using the guest couch in the office would also be possible, but that would always be a bigger hassle with bed linens, stuff, etc., than just having to pull the door shut.

Instead of planning the perfect plan for all life phases, it might be more sensible to make a good plan for the next 10 years.

And what happens after those 10 years? Building a house, especially at current prices, is so expensive that I would like to get more than 10 years out of it. And I know so many people whose children have moved out and the parents then live in a much too large house, much of which they no longer use. But you still have to clean it now and then. With the partition, you would have 3 options:

1. One of the children stays in the house but will then live there in the future with his/her "own" family. Especially as a young couple, one wants even more privacy, which would be provided here.
2. You rent out a floor to a stranger and can afford quite a bit more per year this way, such as a nice vacation.
3. There is a conflict in the marriage at some point, and you wouldn’t necessarily have to plan a rushed move-out. If this does happen, you can still rent out a floor, or if both move out (because support is too expensive), even both floors.

A single-family house that is supposed to become a two-family house at the same time usually doesn't work. Either it doesn’t result in a decent layout for one family, or the second residential unit fails. It’s something like squaring the circle.

Before you draw in 3D – by the way, you can now really have the perfect layout, and if you have a plot of land it is only for temporary storage – create a room program. Include the dimensions for all desired or existing furniture. Gather information by digging through model homes and catalogs. Pay attention everywhere – also with friends and acquaintances – to what you like about the feeling of the space, etc., as well as what you don’t like. This way you get a sense for spaces. When you slowly learn what to pay attention to, many things become apparent. For example, that you plan a WC where you hit your elbows, or a seating place where Aunt Erna will never get past Grandpa Helmut. Use this time to absorb all these little things like a sponge. Nothing is as annoying later as having to realize that to open the oven you have to stand to the side because there isn’t enough space between the oven and the peninsula.

That a house becomes too big for a family later on is normal. Who do you want to have in the house later? A stranger, your own children, or would you rather sell and enjoy retirement in the warm south?
A two-family house rented out to strangers has different requirements again. Separate meters, parking spaces, etc. If it becomes a multi-generational house with your own children and grandchildren, everything is more open without strict separations.

This "draft" most closely resembles a teenager playing Sims.

No no, well when I was still a teenager (around 2000) such nonsense didn’t work in Sims either. (More the other way around, the Sims always needed an incredible amount of walking space to pass each other)

No idea what you mean by your orientation, I chose the cardinal directions so that the terrace is on the south side, just like the solar collectors. The street can theoretically be either in the north (running west to east) or in the east (running north to south). As previously described, I am well aware that regulations still have to be observed with a property here.

I just meant that north should be at the top of the plan. Unfortunately, you have south at the top.