How much space in the world's tallest buildings is actually uninhabitable?
This question prompted the Council on Tall Buildings and Urban Habitat to produce a new report examining "vanity height," the distance between a skyscraper's highest occupiable floor and its architectural top (including spires but not antennae, signage, flag poles, or other functional-technical equipment.)
The graphic below shows the top 10 tallest vanity heights in the world, comparing only the portion of each building above its highest occupiable floor. (click to see a larger version)
As you can see, it turns out that most of the world's tallest buildings are doing, as our colleagues over Quartz put it, "the architectural equivalent of wearing platform shoes." Some other key findings from the CTBUH:
Without vanity height, 44 of the world’s 72 "supertall" buildings (defined as more than 300 meters) would be less than 300 meters, losing their “supertall” status.
New York City has two of the top 10 tallest vanity heights in the world and the city will gain a third when the new One World Trade Center opens in 2014.
The vainest building overall is Ukraina Hotel in Moscow, Russia, with 42 percent of the building uninhabitable.
The vainest "supertall" building is the 321-meter Burj Al-Arab in Dubai -- 39 percent of it is spire. (shown below)
- United Arab Emirates, China, and the United States, on average, have the most buildings with the most vanity height. While the UAE leads with an average vanity height of 19 percent, the country also built the least vain very tall building in the world -- the Index in Dubai has just 4 meters of vanity height, just 1 percent of the building’s overall height. As the second pie chart below shows, large vanity heights in tall buildings is not a new phenomenon.
The above pie charts are visualized based on ratios.
According to Daniel Safarik, editor at the CTBUH, big vanity heights have shown up in buildings since the late 1920s and early 1930s. The difference now is that there is a proliferation of supertall buildings overall. Safarik says buildings are now in more frequent contention for "world’s tallest," which becomes an incentive for developers and owners to put extra materials above the floors they’re able to rent. "There is good reason to create something that will have more lasting power, in terms of its iconicity," he says. Safarik points out that vanity height is fairly consistent across the tallest buildings (with uninhabitable space typically taking up around 30 percent of the total building), which suggests that adding vanity height is not purely a grab for absolute height, but to "cement the building as an icon."
Safarik says although the vanity spaces probably do hold some mechanical equipment for elevators or air conditioning, there is certainly no requirement that the uninhabitable spaces be that large. These findings naturally question the motivations behind making a huge percentage of buildings non-occupiable and add to the debate about the sustainability of skyscrapers.
"There is nothing inherently sustainable about a skyscraper by itself, doesn’t matter how many bells and whistles you put into it," Safarik says. "But if a building is located in a transit-rich city, and the iconicity of the building attracts more development and bigger density of people, then the building does have some sustainable value."
In the meantime, the Burj Khalifa can stand tall knowing that even stripped of vanity height, it's still the world's number one.
All images courtesy the Council on Tall Buildings and Urban Habitat.