Semi-detached house: approx. 145 sqm with gable roof - potential for improvement in the bathroom?

Funny, the room layout on the ground floor and upper floor is identical to our house. And I can say, it works!

we have 3.40 in the master bedroom, works great. However, the 2m line at 2.30 from the head end, and a lintel of about 90.

What I also noticed is that because it is apparently a zero knee wall, the 2m line in the bedroom is too far from the wall at the bottom of the plan for me. Firstly, the headboard of the bed couldn’t be very high, it would also be quite oppressive to lie there and, when getting up, you can quickly hit your head. 335 cm width is also quite narrow for the master bedroom.

Yes, that is really extreme. One could take a look during the shell construction... (consider: screed) and if necessary then cut out a bit so that the bed can be pulled further forward.

we have 3.40 in the master bedroom, works fine. However, the 2m line is at 2.30 from the headboard, and a lintel of about 90.

It certainly works, but you have to be aware that there is only about 60-65cm of space between the wall and the bed on each side. You should definitely take a look at the knee wall in a cross-section.

Thanks for your feedback so far! I'll try to address all points as best as I can.

I would already start with the kitchen planning. I think the distance to the kitchen island is too large – but that's just nitpicking.

We are even roughly done with the kitchen planning (see screenshot. Floor and kitchen appliances, especially the sink and cooktop, are not correct yet. They were only used for better visualization).
You mean the distance between the kitchen island and the kitchen counter, correct? We had deliberately chosen that in the plan so you can see how far back we can still move the kitchen island without running into someone cooking when they enter the kitchen through the sliding door. The plan, however, is to make the kitchen island a bit deeper (countertop size about 105 cm instead of 90 cm) and then adjust it so that the kitchen counter and kitchen island align flush at the top. This should move them about 20-30 cm closer together. Also, we like cooking together and wanted a bit more "battlefield" space to maneuver around.

I don’t like the bathroom with the T layout, you open the door and stand in front of the sink.
I prefer the second variant. Our shower is recessed because we have a slightly different staircase design.
So overall: everything is great.

Personal note from experience:
I don’t know where you planned [Raffstores] and where roller shutters are planned, but I would definitely put [Raffstores] in the children’s rooms.
Because that’s the full sun side, and if you always have the roller shutters down, like at this current weather, it’s bad for the kids to play.
With [Raffstores], of course, it works much better. Sun out, still bright.

We think the exact same about the T-bathroom: You stand directly in front of the sink when entering. Besides, we are concerned the shower would be too dark (we would have swapped it with the toilet, as already suggested by ypg), and the passage between sink and bathtub would become a bottleneck if we install a wider bathtub. Therefore, variant 2 is also an idea.

[Raffstores] will only be installed on the large windows on the south side, for exactly the reasons you mentioned.

Swap shower and toilet!
Slide the door to the living room so that something can still be placed behind it.

I already mentioned swapping shower and toilet above. If we choose the T-bathroom, this swap will happen. Currently, we prefer variant 2 as it seems more open in our minds and would probably offer a bit more storage space.
The point about the living room door is good, we hadn’t thought of that! Thanks for the hint.

What I noticed: since it’s apparently a zero knee wall, the 2m line in the bedroom is too far from the wall at the bottom of the plan. First, the headboard of the bed shouldn’t be very high there, it can be quite oppressive to lie there, and when getting up you can probably hit your head quickly. 335 cm width is also quite narrow for the master bedroom.

Correct, it will be a zero knee wall. We planned to build a small shelf behind the bed depending on the actual ceiling height (i.e., in the raw construction measurement, when seen live). Then the bed moves more into the room and you have a small shelf behind it for glasses, books, phone, etc., and maybe small cabinets with drawers would fit underneath. The width is somewhat larger (3.51 m). The floor plan measured up to the roof of the bathroom (3.35 m), but there are still 16 cm extra. Unfortunately, this is not immediately apparent. So with a 1.8 m wide bed, there should still be 80 cm of space on each side. It’s not ideal, but sufficient for us.

Funny, the room layout on the ground and upper floor is identical to our house. And I can say, it works!

Funny, and good to know that the layout works! Is there anything you would have done differently now that you have gained experience living in the house?

Currently, option 2 appeals to us more because it seems - at least in our minds - more open and would presumably offer a bit more storage space.

Oh dear... it looks more open because the walls look like nothing from above. Besides, you have drawn an absolutely super-duper space-saving tub there, and without any shelf or such. If anything, I would go with the classic shower as in V2 but rotated, and next to it a straight tub boxed in. Toilet only with a half-high privacy wall, if at all.