Petronas Twin Tower

Designed by Argentine-American architect César Pelli, the Petronas Towers were completed in 1998 and became the tallest buildings in the world on the date of completion. The 88-floor towers are constructed largely of reinforced concrete, with a steel and glass façade designed to resemble motifs found in Islamic art, a reflection of Malaysia's Muslim religion. They were built on the site of Kuala Lumpur's race track. Because of the depth of the bedrock, the buildings were built on the world's deepest foundations. The 120-meter foundations were built by Bachy Soletanche, and required massive amounts of concrete.
In an unusual move, a different construction company was hired for each of the towers. According to both a National Geographic documentary and a Korean newspaper, Tower 2 was successfully completed by Samsung Constructions, Kukdong Engineering & Construction (both of South Korea). However, the builders of Tower 1, Hazama Corporation (Japan), ran into problems when they discovered the structure was 25 millimeters off from vertical[6] [7]. The shopping mall beneath both towers was constructed by Birmingham, Alabama-based Bill Harbert International.
Due to a lack of steel and the huge cost of importing steel, the towers were constructed on a cheaper radical design of super high-strength reinforced concrete. High-strength concrete is a material familiar to Asian contractors and twice as effective as steel in sway reduction; however, it makes the building twice as heavy on its foundation than a comparable steel building. Supported by 23-by-23 meter concrete cores and an outer ring of widely-spaced super columns, the towers use a sophisticated structural system that accommodates its slender profile and provides from 1300 to 2000 square metres of column-free office space per floor.
Below the twin towers is Suria KLCC, a popular shopping mall, and Dewan Filharmonik Petronas, the home of the Malaysian Philharmonic Orchestra.
Petronas, Malaysia's national oil company, set out to build the world's tallest building. Although other buildings such as the Sears Tower have higher occupied floors, a higher antenna, and a higher roof, the Petronas Twin Towers' spires are classified as architectural details and rise to 452 m (1483 feet), giving it the greatest structural height until Taipei 101. Taking advantage of the rules governing building measurements (counting spires but not antennas) has generated controversy over the towers' claim to the title. However, the tradition of including the spire on top of a building and not including the antenna dates back to the rivalry between the Chrysler Building and the 40 Wall Street.
Other buildings have used spires to increase their height but have always been taller overall to the pinnacle when trying to claim the title. In the aftermath of the controversy, the rules governing official titles were partially overhauled, and a number of buildings re-classified structural antenna as architectural details to boost their height rating (even though nothing was actually done to the building).