I only had 4m² when I was a small child!
Unimaginable.....YOU are actually still alive? You can't look at such things in general and tie them to "standards," from the basement to the children's room. It has to fit individually, unfortunately I often read "standard" nonsense and way too little individuality, which is at least one reason why I am building myself. I have a Great Dane and go through the mud with her daily, children's screaming annoys me or children's screaming touches my heart, I like to listen to music alone, my partner likes to smoke her hookah in the evening and listens to marching music......etc. pp. This is generally felt to show up way too little here. How do I live, what makes my life, do I also like distance from my partner or are we like a bundle 24/7. A few days ago, asked exactly that in another thread..... but got zero answers except that TE needs eating/living/sleeping/working/floor heating/heat pump and since 2020 everyone really needs home office....yawn. It often goes unmentioned that of course KNX (because of the scenes...), photovoltaics (a bit of being bio), KfW house...... (eco... respectively state coal). But all that really says NOTHING about a house in which I can feel comfortable as an individual person, but about the other "stuff" 70% is talked about..... and where you still get subsidies. Preferences, habits of life, etc. that make my life nice-----not a trace. I read that I am building a KfW55 house..... ok... and what does that tell me? Or a city villa...... ok... and now? Who are you, what do you like, how does your life take place. Even reading about the same high-tech cooking hob or an equally cooking football field with of course a lowered chassis, although not many like and cook well...... all that repeats itself. You can have it all but where are the different people with their strange peculiarities that you are allowed to live at home and that make us who we are? I have the feeling that the more possibilities and Pinterest there are, the more people keep locking into the same thing out of herd instinct, and certainly not because of costs, because it does not necessarily have to be more expensive if you design it individually, maybe even cheaper. From this point of view, it is almost irrelevant whether the children's room has 10 or 30 sqm, it is about the content of the room AND!!! especially about the surroundings! A psychopath can become one in a 50 sqm children's room just as well as in an 8 sqm with curtain, although I would rather expect that from the 50 sqm type. I can't see the point of building a child 20 sqm and limiting the entire living space to 37 sqm and snipping centimeters off every corner. Maybe then I simply won't build at all.
However, the house was already there when I came, so I can't conclude that my parents wanted to get rid of me particularly early.
"Modern" (or rather: today's) parents tend rather to keep their children with them as long as possible or not to lose access. When I hear today what parents want to know about their children, it horrifies me. A well-known child psychologist said about this: I had a great childhood myself – my parents never had time!