ADVENTURER0:

It's a race for the sky .... Around the world, cities are getting taller as architects design buildings they hope can compete for that coveted title of 'tallest building in the world'. But it isn't always easy to determine which building is the tallest. Some buildings have tall spires that reach up into the sky. Some have long antennas used to send and receive radio waves.

It's a race for the sky ... Around the world, cities are getting taller as architects design buildings they hope can compete for that coveted title of 'tallest building in the world'. But it isn't always easy to determine which building is the tallest. Some buildings have tall spires that reach up into the sky. Some have long antennas used to send and receive radio waves.
ADVENTURER1:

If a building has a tall antenna at the top of it, should that count in the measurement? Should a spire? When the Petronas Twin Towers in Kuala Lumpur, Malaysia were built, controversy arose because the spire extended nine meters higher than the roof of the Sears Tower, which until then had been considered the tallest building in the world. So how do we determine which building is the tallest? Well, it depends on the criteria you use to measure the building.

If a building has a tall antenna at the top of it, should that count in the measurement? Should a spire? When the Petronas Twin Towers in Kuala Lumpur, Malaysia were built, controversy arose because the spire extended nine meters higher than the roof of the Sears Tower, which until then had been considered the tallest building in the world. So how do we determine which building is the tallest? Well, it depends on the criteria you use to measure the building.
ADVENTURER2:

There are four categories which are currently used by the Council of Tall Buildings and Urban Habitat. 1.. Height to Architectural Top - Height is measured from sidewalk level of the main entrance to the architectural top of the building, including spires, but not including antennas, signs or flag poles. This is the measurement which is most widely used.

There are four categories which are currently used by the Council of Tall Buildings and Urban Habitat. 1. Height to Architectural Top - Height is measured from sidewalk level of the main entrance to the architectural top of the building, including spires, but not including antennas, signs or flag poles. This is the measurement which is most widely used.
ADVENTURER3:

2.. Highest Occupied Floor - Height is measured from sidewalk level of the main entrance to the highest continually occupied floor within the building. This measurement doesn't count spires and it only measures up to the floor where people can be. 3.. Height to Top of Roof - Height is measured from sidewalk level of the main entrance to the highest point of the building's main roof level, not including spires or antennas.

2. Highest Occupied Floor - Height is measured from sidewalk level of the main entrance to the highest continually occupied floor within the building. This measurement doesn't count spires and it only measures up to the floor where people can be. 3. Height to Top of Roof - Height is measured from sidewalk level of the main entrance to the highest point of the building's main roof level, not including spires or antennas.
ADVENTURER4:

4.. Height to Tip - Height is measured from sidewalk level of the main entrance to the highest point of the building, whatever that might be, thus including antennas, flagpoles and signs. Which do you think should be used to decide? Nobody can agree.

4. Height to Tip - Height is measured from sidewalk level of the main entrance to the highest point of the building, whatever that might be, thus including antennas, flagpoles and signs. Which do you think should be used to decide? Nobody can agree.
ADVENTURER5:

But category one, Height to Architectural Top, is the most common. There is one thing that everyone can agree on. A building can only be recognized as the "World's Tallest Building"" if at least 50%% of its height is made up of floors which can be occupied by people. So .... Structures such as the CN Tower in Toronto or the Oriental Pearl Tower in Shanghai are not in the running to be considered for the "World's Tallest Building".

But category one, Height to Architectural Top, is the most common. There is one thing that everyone can agree on. A building can only be recognized as the "World's Tallest Building" if at least 50% of its height is made up of floors which can be occupied by people. So ... Structures such as the CN Tower in Toronto or the Oriental Pearl Tower in Shanghai are not in the running to be considered for the "World's Tallest Building".
ADVENTURER6:

So, which building is the tallest in the world? Well, every year or two it seems that there's a new winner, and it's a race that'll probably never end. The record has been held by the Empire State Building, built in New York in 1931.. The Sears Tower, Chicago, completed in 1974.. And the Taipei 101 in Taiwan, built in 2004..

So, which building is the tallest in the world? Well, every year or two it seems that there's a new winner, and it's a race that'll probably never end. The record has been held by the Empire State Building, built in New York in 1931. The Sears Tower, Chicago, completed in 1974. And the Taipei 101 in Taiwan, built in 2004.
ADVENTURER7:

This race to the sky is so serious and competitive, that in 2009,, as the Burj Dubai skyscraper was under construction in Dubai, the United Arab Emirates, Its final height was kept secret due to fear of competition from other buildings which were under construction at the time. The developers of this skyscraper were aiming for the title of "World's Tallest Building", but didn't want any other construction company to find out the exact height their building would be, in case their rivals built a new building just that little bit higher and 'stole'' the record!

This race to the sky is so serious and competitive, that in 2009, as the Burj Dubai skyscraper was under construction in Dubai, the United Arab Emirates, Its final height was kept secret due to fear of competition from other buildings which were under construction at the time. The developers of this skyscraper were aiming for the title of "World's Tallest Building", but didn't want any other construction company to find out the exact height their building would be, in case their rivals built a new building just that little bit higher and 'stole' the record!
ADVENTURER8:

It just goes to show there will always be new contenders in the race to build the tallest building in the world. I can't wait!

It just goes to show there will always be new contenders in the race to build the tallest building in the world. I can't wait!