A look at the tallest buildings in the world – Part 3

The issue of tall buildings has proved contentious over the years. It is little wonder the whole debate has arisen since it’s fuelled by an undetermined measuring criteria that for years couldn’t decide whether the roof or the spire was the highest point of a building or indeed what differentiates a building from a tower.

The confusing issue led to many quarrels over which building was tallest, and more recently, those debates have been between various countries. For the better part of the 20th century America led the way for tall buildings, structures and towers. But since 1996 (when the Petronas Twin Towers opened in Kuala Lumpur), Asia has competed for skyline space.

The Council for Tall Buildings and Urban Habitat (CTBUH), who maintain the definitive guide to super-structures decided on a four-part criteria for measuring and therefore differentiating between tall buildings, towers and structures. This was based on the way the top of buildings were measured. For example, the newly opened Shanghai World Financial Centre has an occupied floor that exceeds the height of Taipei 101’s highest occupied floor, however, both Taipei 101 and Sears Tower are taller based on the height between ground level and their highest point. This is because both Sears and Taipei have antennas on their roofs that further their height. Instantly, you can begin to see where the confusion lies.

The CTBUH tried to simplify things. Therefore they define tall buildings by a four-part criteria first and then on usage determining type. A “building” has to have over 50% of occupied, usable floor space; below 50% and it is defined as a “tower”. Once a building or tower is defined, its height is then measured either to its architectural top, its highest occupied floor, its roof, or to the highest tip.

The CTBUH view the architectural top as including spires and other aesthetic design elements but not antennas, signage or flag poles. This is the most common way lists of tall buildings are compiled. The highest occupied floor has to be continually in-use by patrons or employees. The height of the roof doesn’t take into consideration spires or antennas measuring to the highest roof level, while the highest tip measures to the uppermost point regardless of architectural design, antenna or occupied floor space. We therefore get a few buildings vying for the tallest as they each have individual traits that single them out.

Until recently, Taipei 101 was the tallest building in all four categories