Have you ever actually look for small living spaces in the US? I would be perfectly fine with a 450sf apartment in northern VA, but their almost impossible to find in desirable locations. A large reason for this is the actual cost to construct a building doesn’t increase linearly with apartment square footage. Simply having a smaller apartment doesn’t reduce the amount of space needed for hallways, elevators, or parking spaces. Kitchen’s and bathrooms similarly cost a lot more than large carpeted areas.

This ends up being reflected in renal prices. My building has a 578 sf studio @ 1515$/month where a 751 sf 1br is running $1,625/month. Add in parking and your talking 30% more space for 7% more rent.

It’s not that the actual cost per SF is equivalent, it’s that housing got upsized without much input from consumers.