Floor plan planning shortly before submitting the building application

I would combine the boxing-in with a shelf at the head of the bed. Possibly with integrated lighting. Books and/or stuffed animals right at hand at the head of the bed... Your other little one will probably want such a solution too. Without a pipe.

I would combine the boxing in with a shelf at the head of the bed. Possibly with integrated lighting.

And then put the light switch under the windowsill? Will my daughter still be able to reach it easily?

I would probably look for a way to run the pipe in the guest bathroom through the exterior wall, like with a range hood. So still below the ceiling, above nose height

It is not about the ventilation in the bathroom but about the pipe ventilation.

That was what he was referring to as well. Just google the mentioned product.

And the light switch then under the windowsill? Will my daughter still be able to reach it well?

I would rather box off the long side at the bed, if at all. Unfortunately, the bed protrudes into the window if it doesn’t have a flat headboard. It stands at least partly underneath it. Apparently, only a child's bed was planned here. But those become 140cm or even 160cm wide from around age 14-15. Then it protrudes clearly into or under the window, and the box at the head end would look very odd.

I took some more pictures today so that you can better visualize the spatial situation. The offset of the pipe at the top results in an even larger boxed-in area. You can also see the light switch and the sockets. The cables there cannot be extended arbitrarily.

I would probably look for a way to route the pipe in the guest bathroom through the exterior wall, like with a range hood. So just below the ceiling, above nose height

That was already discussed regarding exhaust air / recirculated air. Exhaust air was strongly discouraged because of the insulation, and anyway, it’s not a good solution if you are using controlled residential ventilation.

That’s what he was getting at. Just google the mentioned product.

I’ll inquire.

Unfortunately, the bed extends into the window if it doesn’t have a flat headboard. It at least stands underneath it. Apparently, only a child's bed was planned here. But at some point around 14-15 years old, beds are 140cm or even 160cm wide.

You are right. With or without the boxed-in area, it doesn’t look good. The placement was poorly chosen by us. Unfortunately, now it can probably only be changed with high additional costs (electrician).

I like the bed under the window... you can nicely look at the sky while lying down.