[njepa]

The sensible limit is around 25 square meters / 250 square feet. Any smaller and you start losing function exponentially.

The amount of organizations, businesses and cultural things started from couches, kitchen tables or hobby rooms are plenty. Certainly not something to be underestimated as a benefit to society.

[ghaff]

Something about that size seems like pretty much the bare minimum. My point of reference is a hotel I often stay at in NY which makes something of a virtue of its small "cabins." They're 170 sq. ft. and the minimally separated bathroom is about as small as you could make it. There's a bed and a minimal desk (maybe a few square feet) and desk chair. No closet, no kitchen or even room for a mini-refrigerator or hotplate, etc. Add 80 sq. ft., make the bed a futon, and you start to be a place where one person could almost live out of a suitcase but it would still be pretty minimal for any length of time.

[KozmoNau7]

I lived just fine on 16m² for 2½ years, and I had plenty of space for everything I needed to do. I could have 3-4 people over in comfort, any more and we just used the common room or a nearby cafe.

[njepa]

I have lived in smaller as well. But the point is that somewhere around 25 square meters you start taking away functional space. There is a big difference between a 120 cm wide bed and a 70 cm wide bed, or a 90 cm cook top and a 45 cm cook top, or 140 cm wide desk and a 70 cm wide desk. But the same isn't necessarily true as you go up. It is nice to have a bigger kitchen, but the utility diminishes. Or at least per unit of space. While just having a hot plate is likely to decrease ones likelihood of e.g. eating healthy.