Usable space is what it sounds like, how much space people can use on a building. For a good example, the Burj Khalifa, has 200 floors but you can only use 160! That means it’s only 2 meters higher than Shanghai Tower in usable space.

There was also an article called “Tallest Buildings of 2020” That time, there were 8 supertall buildings in the world. (A supertall building is a building that’s taller than 600 meters.) And surprisingly enough, because of usable space, there were only 3 of them, in 2021. Which contains: Albraj Al Bait, Burj Khalifa, Shanghai Tower.