CN Tower
"Guinness World Records" has called the CN Tower "the world's tallest self-supporting tower" and "the world's tallest free-standing tower". Although Guinness did list this description of the CN Tower under the heading "tallest building" at least once, it has also listed it under "tallest tower", omitting it from its list of "tallest buildings." In 1996, Guinness changed the tower's classification to "World's Tallest Building and Freestanding Structure". Emporis and the Council on Tall Buildings and Urban Habitat both listed the CN Tower as the world's tallest free-standing structure on land, and specifically state that the CN Tower is not a true building, thereby awarding the title of world's tallest building to Taipei 101, which is shorter than the CN Tower. The issue of what was tallest became moot when Burj Khalifa, then under construction, exceeded the height of the CN Tower in 2007 (see below).
Mark Sarkisian
Sarkisian has designed over 50 major building projects around the world including the Embassy of the United States, Beijing, the NBC Tower in Chicago, the Cathedral of Christ the Light, St. Regis Museum Tower a 42 story tall building in San Francisco, Rolex Tower a 59 story tall tower in UAE, Zifeng Tower an 89 story tall building, Tianjin World Financial Center a 74 story tall building in China, the Jin Mao Tower - currently the fifth tallest building in the world, and the 415 meter-tall Al-Hamra Tower in Kuwait.