Within this decade we will likely witness not only the world’s first kilometer-tall building, but also the completion of a significant number of buildings over 600 meters (around 2,000 feet) – that’s twice the height of the Eiffel Tower. Two years ago, prior to the completion of the Burj Khalifa, this building type did not exist. And yet, by 2020, we can expect at least eight such buildings to exist internationally. The term “supertall” (which refers to a building over 300 meters) is thus no longer adequate to describe these buildings: we are entering the era of the “megatall.” This term is now officially being used by the Council to describe buildings over 600 meters in height, or double the height of a supertall (see Figure 1).
|Figure 1. Diagram of the predicted World's 20 Tallest in the year 2020 as of Dec 2011|
As we started the 21st century, just 11 short years ago, the Petronas Towers held the title of “The World’s Tallest” at 452 meters (1,483 feet) in height. Taipei 101 took the title in 2004, at 508 meters (1,667 feet).Then, at the end of the decade, the Burj Khalifa set new standards at 828 meters (2,717 feet) – over half a mile high. Now, with work set to start on-site in January 2012 for Jeddah’s 1,000+ meter Kingdom Tower (see Figure 2), we can expect that in a mere two decades (2000–2020) the height of the “World’s Tallest Building” will have more than doubled.
|Figure 6: A study of the tallest 20 buildings per decade.|
It is also useful to understand the tallest 20 in 2020 in the context of global tall building trends. The average height of these twenty buildings is predicted to be 598 meters (1,962 feet). Yet, as we stand at the end of 2011, there are actually only 61 buildings currently in existence over 300 meters (the threshold for “supertall”). Until recently, in fact, the completion of a supertall was rather a rare occurrence, with only 15 supertalls completing in the 65 years between the world’s first such building (New York’s Chrysler Building, 1930) and 1995. It was only in the mid 1990s that it became common for more than one supertall to be added to the lists annually, with 1995 being the last year when no supertalls were completed. Now, less than two decades later, the number of supertalls completed annually has entered double digits, and is set to continue to rise. Meanwhile, the number of megatalls set to complete in the upcoming decade is similar to the number of supertalls completed in the 90s (see Figure 7). In terms of height, therefore, 600 m seems to be the new 300 m.
|Figure 7: Supertall and megatall building completion showing a significant projected increase,|
Note: The figures for following years are estimates based on current building trends and construction activity.
Not only increasing in height, the “Tallest 20 in 2020” also demonstrate a diversity in project location not previously seen in the world’s tallest 20. The projects are scattered across 15 cities in 7 countries. China, with 10 of the 20 projects, clearly stands out as the country most rapidly pursuing the supertall, followed by Korea (3), Saudi Arabia (2), and the UAE (2). If we analyze via a larger geographic region, however, the picture becomes even more pronounced. Asia (not including the Middle East) accounts for 70% of the buildings (14). The Middle East counts for 25% (5). The only other region to be represented in the study is North America, where New York’s One World Trade Center is the only tower in the western hemisphere to make the study. If we consider the Middle East as part of continental Asia, then Asia contains 19 of the 20 projects.
With over 1.3 billion citizens and a rapidly urbanizing population, China is perhaps the country with the most obvious reason for building tall. The ten Chinese projects show great diversity in location, spread across seven cities: Shenzhen (2), Shanghai (2), Tianjin (2), Wuhan (1), Guangzhou (1), Dalian (1), and Taipei (1). The tallest of these, Shenzhen’s Ping An Finance Center (see Figure 8), is now under construction and scheduled to complete in 2015. Once complete, the project will provide over 300,000 m2 of office space and become the country’s tallest building and the world’s tallest office building. Also in China, the 632-meter (2,073 feet) mixed-use Shanghai Tower (see Figure 9) will complete a supertall cluster in the city’s Pudong area, as it sits alongside the Shanghai World Financial Center and the Jin Mao Building. The Shanghai Tower’s unique dual-skin design provides atrium space containing “gardens in the sky” between the skins every 12 – 15 stories. The project began construction in 2009 and is scheduled to complete in 2014.