AROUND THE WORLD
What has happened ?
The prize for the tallest building was first competed for when in 1439 , the Strasbourg Cathedral outstripped the Lincoln Cathedral as the tallest building , this remained the tallest building until 1884 , when the first skyscraper , the Home Insurance Building , which had 9 floors . The race to be the tallest building in the world intensified in the 20th century when by 1998 , the number of floors had increased tenfold . From 1908 to 1998 , the world ’ s tallest building was either in New York or Chicago , but that was going to change . At the turn of the 21st century , the race shifted away from the west to Asia and the middle east . While the Burj Khalifa remains the world ’ s tallest building , many more mega tall buildings have been built . A mega tall building must measure over 600m . The mega tall club has the Shanghai Tower , Mereka Tower , Makkah Royal Clock Tower and the Burj Khalifa as its members .
The reason for building these skyscrapers was mainly about status , but also about housing and putting as many people in one building as possible . Allowing relatively small pieces of land to accommodate large buildings did have the advantage of reducing urban sprawl . Many of these buildings were actually paid for by Governments rather than the private sector developers in the past . This was a way of saying “ our country is prosperous ” rather than an attempt to deal with any housing or office demand .
An amazing fact about the Burj Khalifa is that only 160 floors of its 200 floors are useable , this extra height above the useable floors is called vanity height .
There are 10 mega tall buildings in the world which have given the designers real design challenges but with ingenuity , these have been overcome . Certainly , it is possible with the current technology and ingenuity that we are able to build higher which is evident by the planned Jeddah Tower in Saudi Arabia which was designed to be 1 000m tall , by far the highest building in the world . This however was put on hold in 2018 at one third complete .
So why are there no mega tall buildings planned ?
• China has the 10 tallest buildings in the world but there are now restrictions on buildings over 500m as well as a ban on what they call “ ugly architecture ”, which most of us would agree with except the architects .
• They are also wanting to reduce the number of vanity projects which waste money and electricity having unusable floors .
• Currently the demand for high-rise office space has seen a 26.4 % vacancy .
• Health and safety concerns with mega tall buildings .
• The hugely higher cost of construction .
• The inefficiency of the buildings as the cores are far larger in relation to the lettable area as the cores need to provide far more services than a lower building .
• The reduced return on investment due to the higher cost , inefficiency of the buildings and the unusable upper floors .
With the pressure on developments to be greener and buildings needing to be more desirable , nicer places to work , the demand for tall buildings is decreasing . Tall buildings are becoming less green the higher they go because :
• They negatively impact on their surroundings , as with the large number of people working in the buildings this is putting pressure on existing services .
• Building skyscrapers is essentially bad for the environment and they have double the carbon footprint than a 10-storey building of the same floor area because of the extra foundations and to stop the building from swaying .
• So many of the large buildings have glass facades as the sunlight can get in but has no way of escaping so you are effectively fighting the environment rather than working with it by having to use massive air-conditioning plants .
Luckily , we don ’ t have the dilemma in Botswana of whether to build a megabuilding or not , but at Time , we have made our name on building low-rise low-density buildings which we have always been able to let as they are efficient , cost effective and really great places to work .
ISSUE 51 - SEPTEMBER 2022 13