Guest bathroom planning

I would leave option Original. There was recently a discussion about the space requirements of the restroom.

You can invite the sanitary planner to his proposal. But he should keep his knees in when at the business and always lock the door diligently. :)

But Original and Saniplaner are equally matched. The space remains the same.

I would probably prefer Saniplaner as well and consider whether to possibly open the door outward.

Toilet and sink on one wall is IMHO better. I would then swap the two elements.

I also prefer the second option. It also has the advantage that the light falls on the washbasin from the side.

Thank you for your feedback, we also prefer option 2 and it also creates more space. But I don’t think swapping the toilet and the sink is possible because the window is on the right. If a pre-installation wall has to be placed in front of the sink, as shown, the sink would stand in front of the window. That’s my amateur opinion :)

So is the parapet height of the window lower than the washbasin height?

I don't know how high such a washbasin comes. The sill height is 1m for the window. I also wonder if a pre-wall installation is necessary for the washbasin; if not, you would have saved a good 20cm.