Window size ratio to room size - experiences?

Good day

Since we are building a house next year, we are now planning.
I was told that the windows must have a certain size relative to the room size.

Does anyone know how this is regulated? House construction takes place in Upper Austria.

Best regards

Ask your architect. But no matter where you build, due to the brightness desired by all people in the rooms (who wants to live in a bunker anyway), the question is only theoretical.

The total area of the lighting openings of living rooms and naturally lit common rooms must be at least 10%, and at a room depth of more than 5 m at least 12% of the floor area. Oberösterreichisches Bautechnikverordnung - OÖ BauTV 1999, ob aktuell, keine Ahnung

That is then just bunker style. It is a subjective topic how bright the room should be to feel comfortable. I think in normal bedrooms/AZ/KZ... it should already be 20%, but it also depends on the direction and the development of the surroundings. In the living room/dining room/kitchen... it can also easily be 60-80%. But the perception is very different, for my wife it is actually too open, I would have also liked even more glass.

As a rule, too much window area is built today, that is the trend. However, I would not go below 20% of the floor area.

We have a good 40% in the living room and dining room, which is very bright and more than sufficient.

In the living room/dining room/kitchen... it can also gladly be 60-80%. But the perception is very different, my wife actually finds it too open, I would have liked even more glass.

How is one supposed to realize that?

Best regards
Sabine