Planning the garage location at the single-family house

What immediately catches the eye is that on paper, Child 1 and 2 are the same size. However, Child 1 has virtually nothing from about 1.5 to 2 sqm in the entrance area.

I also like the floor plan. The kitchen topic has already been addressed.
For the staircase, I would make sure that it appears "light and airy" and does not overwhelm the entire hallway, since it is already very central and dominant in the hallway. I once visited a show house in Ottendorf-Okrilla near Dresden that had a similar hallway.
For the study, you should consider the furniture layout. It is nicely bright, but the second window also reduces wall space. However, judging from the exterior views, the second window is probably necessary.

The staircase immediately caught our eye in the 3D view as well; it almost appears too dominant in the hallway! How do you like the bathroom? Isn't it too dark, especially in the area where the shower is located?

If I remember correctly, the model house had a staircase with stainless steel railings and stone steps. This made the hallway appear more open. Alternatively, glass would also be an option.

I find the bathroom itself quite nice and spaciously designed. But to be honest, I don't quite understand how the bathtub is installed. It "hangs" somewhere freely in the room, or is it supposed to be a corner bathtub?
Regarding the shower: If you build a ceiling-height wall at the back, it can get a bit dark. Of course, you can balance that out with appropriate lighting, but especially in summer it's nice to shower in daylight.
How about instead a half-height wall with a glass partition above it? Or a whole shower wall made of glass?

I don't see the lighting problem. Surely no daylight gets in there, but there is always artificial light that can be planned for that area. Certainly, a glass wall is also an alternative, but you have to clean it every time.

Basically, half-walled showers serve exactly the purpose of allowing you to do without glass and being private due to the visual barrier. If someone doesn't want to accept the compromise of artificial light, they can install a normal corner shower. These T-solutions are a kind of fad, but a tiled half-wall makes more sense.

And while many showers today are somehow squeezed into the bathroom, I really think the placement here is quite well done :)

I honestly don't quite understand how the bathtub is installed. It "hangs" somewhere freely in the room, or is it supposed to be a corner bathtub?

Certainly, this tub will get a half-wall or a pedestal.