Window size ratio to room size - experiences?

Well, our living room "area," for example, is about 5x6m and 2 walls are mostly made of glass. That makes about 25/30 = 83%. The kitchen is about 4x3m with 2 windows totaling about 5.5m², which makes 46%. This is nothing particularly extraordinary. More than 20% is therefore not a problem.

how is that supposed to be realized?

Clear ceiling height simply set to 4m+ - or plan the dining room right in the conservatory

Usually, nowadays too much window area is built, that is the trend. However, I would not go below 20% of the floor area. We have about 40% in the living room and dining room, that is very bright and more than enough.

Well, our "living room" area, for example, is about 5x6m and 2 walls are largely made of glass. That makes about 25/30 = 83%. The kitchen is about 4x3m with 2 windows of about 5.5m² which makes 46%. This is nothing overly special. More than 20% is therefore not a problem.

Two walls largely made of glass or 40% is simply exaggerated if you assume a normal standard single-family house. Of course, you can do it, but then there must also be compensating area for the living space because a family of four still wants to put some furniture. Yes, it looks great when building puristically and with lots of glass, but I would seriously consider whether it makes sense to throw out your values for a general question. If someone wants to build puristically, then he has most likely already dealt with it somewhat. If a question like this is asked:

I was told that the windows must have a certain size relative to the room size.

Then it is definitely about the basics. And yes, I agree with you there: if 10% according to DIN is estimated, then base something on that. But definitely not 3-4 times that... For example, we have about 15 sqm in 60 sqm, distributed on 3 sides. Nevertheless, I have found that we could do without 4 sqm because the room eventually becomes saturated with brightness. Beyond that, optics come into play, and they are known to be subjective.

As written, very subjective. However, in my opinion, the 10% are not even applicable to prisons... Our utility room/HAR has 10m² and a 1m² window. Even at 1 p.m. in midsummer with bright sunshine, it is so dark inside that you have to turn on the light for anything more detailed than roughly finding something.

Thank you for your answers. Are the 10% referring to the glass area or the window size?? Does this apply to all rooms??

Thank you for your answers. Are the 10% referring to the glass area or the window size?? Does this apply to all rooms??

In the state building regulations, the rough opening size of the windows is always meant. This applies to all living spaces – so not for corridors, stairwells, or storage rooms.