In some countries, like a poster mentioned, they include the “built” size, not the actual liveable size. Sometimes the balconies are included in that, and it is misleading. Two bedrooms in 900sqf liveable is one thing vs 3 bedrooms in 900sqf built area including balconies.

... Huh. This actually explains something I'd been confused about before; people on this site claiming that a 1000sqft apartment was small. Which, I suppose, if you include the entire footprint of the apartment including balconies, sure. It would never have occurred to me to do it like that.