tech watch: second city

The city of Taipei has dethroned Kuala Lumpur - the Petronas Towers are no longer the "world's tallest" :

TAIPEI (Reuters) - The Taipei 101 office block has attained its full height of 508 metres (1,667 feet), unseating Malaysia's Petronas Towers as the world's tallest building.

At a ceremony on Friday witnessed by officials and business leaders, a 60-metre (197-ft) spire capped the 101-storey structure, officially making it taller than the 452-metre (1,483-feet) twin towers in Kuala Lumpur.

What I like about this tower is what I also liked about the Petronas - the design evokes traditional architecture of the region. Whereas Petronas was an eight-pointed star in the mode of Islamic architecture, the Taipei101 has its own nod to Chinese architectural heritage:

It is one of the few supertalls in the world in which the design inspiration comes from traditional Chinese buildings. The tower's design and specifications are all based on the "8", a lucky number in traditional Chinese culture. This kind of "8-design" was also widely used in the Jin Mao Tower in Shanghai.

It's worth noting however that there are FOUR definitions of "height" when used in ranking the world's tallest buildings:

Tip Height is defined as the vertical elevation from the base to the highest man-made part of the building, or any fixed attachment thereto, whichever is higher. This includes flagpoles, antennae, fences, cooling towers, signs, aircraft warning lights, and all kinds of chimneys. Mobile parts such as extendable signs may be included in the measurement as long as the variation of their heights is regular; in this case the maximum height shall constitute the tip height. Attachments such as flags, loose ropes or wires, and trees shall not be considered.

Structural Height is defined as the vertical elevation from the base to the highest architectural or integral structural element of the building. This includes fixed sculptures, decorative and architectural spires, ornamental fences, parapets, balustrades, decorative beacons, masonry chimneys, and all other architecturally integral elements along with their pedestals.

Roof Height is defined as the vertical elevation from the base to the highest exterior portion of the shell enclosing the building's interior space. This excludes spires, parapets, and other protruding non-habitable elements. In the event of ambiguity between the enclosing "shell" and the projecting element, then the roof's thickness shall be established by setting its height 10 cm above the highest reach of inhabitable space inside the building.

Highest Occupied Floor Height is defined as the elevation from the base to the top of the floor slab of the highest occupiable interior level, excluding mechanical, storage, or stairway penthouses whose walls are set back from the perimeter of the highest non-mechanical floor. In the event that the floorplate is not of uniform level, then its height shall be defined as the median height taken across its entire area.

Until the Petronas Towers were built, the Sears Tower in Chicago held all four titles. Petronas displaced the Sears Tower only by virtue of an enormous spire, which was part of the architectural design but did not actually have usable space. Thus Petronas got a boost to its Structural height by virtue of its spire, but the Sears Tower actually remained the leader in Highest Occupied Floor, and Roof, and Tip. Unfortunately, Structural height is the one used in the public domain to assert the title of Tallest. You can see that the Sears was taller by far in every intuitive sense of the word by looking at the scale drawing below (taken from skyscrapers.org). And the illustration actually omits the Sears' antennae masts. From left to right: World Trade Center NYC, Sears Tower, Petronas Towers.



However, with the advent of the Taipei101, the Sears Tower is truly second-tallest in the Occupied Floor category. Even those of us diehards who have defended the Sears Tower all these years have to admit defeat. But at least the unworthy Petronas are finally unmasked as the impostors they are^[1].

UPDATE: Here's a scale diagram comparison of Taipei101, Sears, and Petronas.

^[1] and since I'm originally from Chicago, and was born in 1974 the same year as the Sears, I'm particularily sensitive to the issue. Imagine if the Yankees were turned into the Red Sox overnight by virtue of a fan catching a ball in the stands for a sense of the injustice. Taipei101 coming online is thus equivalent to the Cubs subsequently beating the Red Sox. The Yankee fans would find some solace in this, I am sure, and I do too.