How much light does a window let in?

I don’t see it on the phone, but at the very top of my post I wrote bw! If he is smart, he will then inform himself about his construction site.

I tinker in Bavaria ;)

If 12.5% is the minimum requirement according to DIN, it can’t be harmful to have more than that. Our living area (with dining and kitchen) gets about 35%, children’s/workroom about 20%.

Bright rooms are inviting, and I have not heard that rooms at the end of the building were too bright

Not that, but especially living/dining rooms where there are hardly any possibilities left to place a cabinet or a chest of drawers, I have seen more often.
For example, I also do not want a living room couch without at least some wall space behind it. In my opinion, you don't feel really comfortable then.
Another argument against overly large windows is privacy from the outside, for example when you already have the lights on in the evening but the blinds are still up.

Arguments against windows: noise, loss of space, heat gain, window cleaning :D

Glass (in the plastic frame) does not cost a fortune and reduces the mason's costs if the panes are floor-to-ceiling.

Generally, walls are cheaper than windows, right? Stones aren't that expensive...