In theory, we're in the midst of a "golden age" of skyscraper construction. But why, of the ten tallest buildings on Earth, is nearly 30 percent of each structure totally unusable spire? This week, the Council on Tall Buildings blew this scandal wide open with a report on the phenomenon, which they've christened "vanity spire."
In truth, this information is readily available to anyone with eyeballs. All supertalls (eg, any building over 1,000 feet tall) have substantial spires and unoccupied upper floors, which serve to house hardware, observation decks, and often, mass dampers that counteract the sway of the building in the wind. But even taking into account the necessary infrastructure, the majority of spires are totally unnecessary.
In fact, without the vanity height, 60 percent of the world's supertalls wouldn't actually be supertalls at all. The Burj Khalifa would lose more than 700 feet. If an angry giant broke off the Burj's spire and planted it on the ground, it'd still be the 11th tallest building in Europe. The worst offender of all is the Burj Al Arab, of which 39 percent is vanity spire (and, uh, vanity tennis court/helicopter landing paid). The UAE does lead the pack, but China and the US are nipping at its heels in the vanity department: New York City alone has three of the top ten tallest spires in the world (the Bank of America tower, the New York Times tower, and One World Trade).
This is a relatively new phenomenon, one that has increased by roughly 400 percent since the mid-1970s. There are plenty of socioeconomic ways to explain why it's increased: The title of world's tallest is traditionally a pissing match between international developers, and as the Skyscraper Index proposes, building height is tied to booms and busts. Spires, after all, are far cheaper than habitable spaces.