Window size ratio to room size - experiences?

You also have to consider the format. Often, you see rather narrow, floor-to-ceiling windows. With the same glass surface, they illuminate the room less than a square or landscape format.

One must also consider the format. Often you see rather narrow, floor-to-ceiling windows. With the same glass area, they brighten the room less than a square or landscape format.

Is that so? I was told exactly the opposite. Now I don't know what is correct.

Is that so? It was explained to me exactly the other way around. I don’t know what is correct now.

Think about the light incidence and also the room geometry. People also see in width and not in height. The sun also moves. In landscape format, you simply have longer (more) light incidence during the day.

Yeah, that makes sense.

Does this 10% rule also apply to the bathroom?

Does this 10% rule also apply to the bathroom?

A bathroom is not a living room. Otherwise, by the way, many apartments would not be allowed to have an interior bathroom at all.