The Dubai building is more than 50 stories higher than Chicago's Willis Tower, formerly known as the Sears, and the tallest building in the U.S. at 1,451 feet (442 meters). The John Hancock Center is the fourth tallest building in Chicago and sixth in the U.S. at 1,127 feet (343 meters). If you stack the Hancock on top of the Willis, the Burj Khalifa will still be taller.
It blew away the Taipei 101 in Taiwan, which at 1,667 feet (508 meters) had held the title of the world's tallest building. And, it also blew past a television mast in North Dakota, which was the world's tallest structure.
"We weren't sure how high we could go," said Bill Baker, the building's structural engineer. "It was kind of an exploration ... A learning experience."
Baker works for Chicago-based architecture and engineering firm Skidmore, Owings and Merrill.
The The Burj is more than twice the height of New York's Empire State Building's roof.
Chicago architecture firm designed Burj Khalifa
The Dubai tower was designed by Chicago architectural firm Skidmore, Owings and Merrill. The Skidmore brand is now on five of the world's 10 tallest buildings.
The exact height of the tower-- 2,717 feet-- was a closely guarded secret, until the ceremony on Monday. It's an architectural marvel that pushes the limits of design and construction.
But completion of the building comes at a time when Dubai's economy has reached its limit and had to be rescued by its oil rich neighbor. To return the favor, Dubai renamed the building the Burj Khalifa in honor of that generous neighbor's leader.
The incredible feat of architecture debuted with a jaw dropping ceremony. The 160 story building is described as a vertical city with a hotel designed by Giorgio Armani, luxury apartments and ample office space. It cost $1.5 billion.
Construction started more than 6-years ago when Dubai's economy was strong, and the tiny city-state was experiencing off-the-charts development. But now, Dubai is in the midst of a deep financial crisis because of the global financial meltdown. It was bailed out by its oil rich sister city of Abu Dhabi. The building was renamed the Burj Khalifa in honor of Abu Dhabi's sheikh.
With all the woes, Dubai's top leaders still sound optimistic. Mohammad Alabbar is the chairman of Emaar, the firm that built the Burj.
"I dont' know any news in the world that stops us from celebrating," said Mohammad Alabbar, chairman, Emaar Properties
The Burj Khalifa was designed by Chicago-based architecture and engineering firm Skidmore, Owings and Merrill, which has designed five of the world's 10 tallest buildings- including the Willis Tower and the Trump Tower. The senior structural engineer on the Burj says it's unfortunate the debut of the building coincides with tough economic times for Cubai but hopes that it becomes an icon for the city.
"All I can say it maybe this is a ray of hope for Dubai, that here's something positive to come out of everything that's going on right now," said James Pawlikowski, Skidmore, Owings & Merrill.
Skidmore, Owings and Merrill can once again claim the world's tallest building. They built the Sears Tower, now Willis Tower, in the mid-1970's, which held that claim until the mid-90's.