I will come back here at the earliest when there are pictures of the situation.
There are, one post before his answer. In my opinion, pictures of the interior are not necessary, or if they are needed, then I will forgo help from the forum.
North is pretty much on the right side of the house. (And yes, I know children's rooms should preferably not face north, the idea was no bedroom directly next to the bathroom.)
Not much more can be derived from the ground floor plan than from my drawing. I have now taken another photo; the changes come from my plan. But right now, I really don't have time for more.
Currently, the bathroom is left of the stairs, near the drain.
And yes, I know about the measurements, but the drawing was available and moving the decimal point is not that difficult.
I know this probably is not meant badly, but I think this is heading in a direction I cannot afford. I actually just wanted to gather a few ideas regarding the floor plan; for everything else, I would have found someone on site. If this only works with an "architect's plan," then unfortunately it probably won't work out.