The Burj Khalifa towers over the Dubai desert at 2,717 feet (828 meters; for this question United States customary units are appropriate), making it currently (as of March 2018) the tallest manmade building in the world. It’s held that record since 2008, and it bests the next tallest skyscraper, the Shanghai Towers in Shanghai, China by nearly 650 feet. (One World Trade Center, the tallest building in the U.S., lags behind at 1,776 feet.)
But guess what, Burj? Your days of being #1 are (probably) numbered. Several projects on the development slate are on schedule to overtake Dubai’s neo-futuristic megatall landmark.
The Jeddah Tower in Saudi Arabia, which will stretch up a whole kilometer above the Earth by 2021
In 2021, Merdeka PNB118 in Kuala Lumpur, Malaysia, will nip at the Burj's heels at 2,113 feet.
The Sky Mile Tower proposed to be built in Tokyo, Japan aims to reach 1 mile in height. But the obstacles are formidable. As CNN reports:
At that soaring height, design requirements for wind can exceed those for earthquakes -- even, according to [a] report [by the Council on Tall Buildings and Urban Habitat (CTBUH)], in the most earthquake-prone regions of the world. "The tower will naturally have long periods of vibration that will be more readily excited by the wind," the report explains.
When will there be a mile-high building?
This question will resolve on the earliest date that a building one mile tall (1,609 meters) is complete and fully open for human occupancy.
If this does not occur before April 1, 2060, this question will resolve as Ambiguous.