ᐅ Window size in relation to room size – any experiences?

Well, our living room "area," for example, is about 5x6m (16x20 ft) and two walls are mostly made of glass. That results in roughly 25/30 = 83%.
The kitchen is about 4x3m (13x10 ft) with two windows totaling approximately 5.5m² (59 ft²), which makes 46%.
This isn’t anything extraordinary. More than 20% is therefore not a problem.

Curly schrieb:

how is that supposed to be realized?

Simply increase the clear floor height to 4m (13 feet) or more – or plan the dining room directly in the conservatory.

Bookstar schrieb:

Nowadays, too much window area is often built; that’s the trend. However, I wouldn’t go below 20% of the floor area.

Our living room and dining area have about 40%, which is very bright and more than enough.

Lumpi_LE schrieb:

Well, our living “area” is about 5x6m (16x20 feet), and two walls are mostly glazed. That’s about 25/30 = 83%.
The kitchen is roughly 4x3m (13x10 feet) with two windows totaling around 5.5m² (59 ft²), making 46%.
This is nothing unusually special. So more than 20% is no problem.

Two walls mostly glazed or 40% window-to-floor ratio is simply exaggerated if you consider a typical single-family home.

Of course, it can be done, but then there needs to be compensating space in the living area since a family of four will still want to place some furniture.
Yes, it looks great if you build in a minimalist style with lots of glass, but I would really think twice before throwing out your numbers in response to a general question. If someone wants to build in a minimalist way, they most likely have already researched it. When a question like this is asked:

Patrickpr schrieb:

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

Then it is definitely about the basics. And yes, I agree with you there: if the standard requires about 10%, then that’s what you should aim for. But not three to four times that amount...

For example, we have about 15m² (161 ft²) of windows in 60m² (646 ft²), spread over three sides.
Still, we realized we could do without 4m² (43 ft²) because at some point the room is saturated with brightness. Beyond that, aesthetics come into play, which is, of course, subjective.

As mentioned, this is very subjective.
In my opinion, the 10% rule doesn't even apply to prisons...
Our utility room has 10m² (108 sq ft) with a 1m² (11 sq ft) window. Even at 1 PM in midsummer with bright sunshine, it is so dark inside that for anything more than roughly finding something, you need to turn on the light.

Thank you for your answers.
Do the 10% refer to the glass area or the window size?

Does this apply to all rooms?

Patrickpr schrieb:

Thank you for your answers.
Does the 10% refer to the glass area or the window size?

Is this valid for all rooms?

In the regional building regulations, the structural opening size of the window is always meant. This applies to all habitable rooms—so not to corridors, staircases, or storage rooms.