you are right about that. Theoretically, the 2 walls could be taken down again but that would come at the expense of the size of the office or children's room and I value living space more there. Besides, I always think 8 sqm is not small. May I ask how you designed your bathroom?
Yes, living space is especially important in an apartment. 7 sqm is enough too, but it is better to give up one meter in length and have 20 cm more in width, but usually the layout of an apartment doesn’t allow that.
Of course, you may ask: Our bathroom is under the roof and has more floor space, and that only for 2 people. However, the shower is on the ground floor as a walk-in shower – for old age. For that reason, upstairs we only have a bathtub, which is sometimes used for showering as well. I could gladly give up the meter in the middle. Personally, I like it when I can throw paper into the toilet with one step without leaving my place at the washbasin. But we use the bathroom separately, except when bathing. In the old house, we had 2.20 m in width and an egg-shaped tub, so two-sided in a corner, which shifted the standard floor plan diagonally. That way you can also gain space. We then adopted that with the washbasin. In my old condominium, I had no window, and there as well the bathtub was used for showering: shorter than your bathroom, but set up the same way as yours without a shower area. Toilet and washbasin opposite and offset to each other. The toilet was closer to the tub; oh yes: next to it was a bidet.
Regards