Last year may have been the most successful year in skyscraper history, but this year looks to be the most exciting, as Saudi Arabia’s Prince Alwaleed has reportedly approved a US $30 billion plan to build the 1001 metre “mile high” Kingdom Tower.
Upon completion, the new tower will be twice the height of Dubai’s current record holder, the Burj Khalifa, and will be surrounded by 8.9 square miles of newly constructed city, accommodating 80,000 residents and one million visitors.
Located in the little-known Obhur, on the outskirts of Jeddah, the development will provide 12 million cubic feet of space for offices, a hotel and residential units. The floor area will total 38 million square feet and it is expected specially designed elevators will take 12 minutes to reach the highest floor.
When facing a project of this size, it’s only natural to tap the knowledge of those who have already achieved such a feat. According to reports in the Saudi Gazette, Burj Khalifa architect Adrian Smith has already been confirmed for this project. Since completing the Burj Khalifa, Smith left SOM Architects to establish his own firm, Smith and Gill.
The structural peer review of the Burj Khalifa, was conducted by Hyder Consulting, who became legally responsible for the design under UAE law. Enhancing the “buildability” of Smith’s design, Hyder standardised the dimensions of the walls and columns; changed the details of the steel work; tested materials — particularly the glass and stainless steel of
the facade — and made it possible to construct the elements which appeared impossible.
“With any type of construction, the more you can standardise it, the more efficient it will become,” explains Hyder Consulting’s John Mills, project director for the Burj Khalifa.
“Obviously a building the shape and size of Burj Khalifa, on the face of it there’s not a lot you can standardise but we did manage. We put a great deal of effort into the facade to keep with the architect’s intentions,” Mills continues.
“The brief was not what would you like to do to change it, but here is an architectural concept; the structure has to be strong enough.
“Our challenges then became rapid re-design where we had to also incorporate buildability elements into the design by jointly working with the contractor.
“They wanted to do construction in one fashion and we changed the design to make it easier for him to do that,” he continues.
Explaining the enormous task of making the Burj Khalifa ‘work’, Mills says even the local building regulations did not anticipate a tower of such a height, with special permission granted by Dubai Municipality to allow partial occupation before the final completion.
“We started piling in January 2004, we had a formal opening in January 2010 and occupation is still going on; that’s a seven year cycle. If you had to fund a project for seven years before you start getting any return on your investment,
that’s a huge capital outlay,” he says.
Upward trend
In addition to the Kingdom Tower, Qatar is planning a record breaker of its own, according to Sheikh Thani Bin Abdullah Al Thani, who is also the chairman of Qatari real estate and property developer Ezdan.
Last month, the Qatar Tribune carried a report that plans for the tower are “in the pipeline” but that land has not been secured.
“For us at the Council on Tall Buildings, it’s exciting to know that these projects are being considered.
“They will undoubtedly produce a lot of new knowledge and insights which can be beneficial to the tall building world as a whole,” says chairman for the Council on Tall Buildings and Urban Habitat (CTBUH), Professor Sang Dae Kim.
According to data compiled by CTBUH, one quarter of the world’s tallest towers are in the
Middle East, with five of the top ten located in the UAE; four in Dubai. Yet considering Mills’ statement that “most of Sheik Zayed Road is higher than New York”, it’s hardly surprising.
“Why do they build these towers? Because they can,” he says, adding: “With Burj Khalifa the money was there, the desire was there. You try and do anything like this in the UK or Europe and you’re bogged down with bureaucracy; for example the M25 motorway was first put in for planning in 1913.
The first length wasn’t opened until 1980. “Effectively the driving force in Dubai is the Maktoum family. If they say yes, you can do anything and Dubai has grown phenomenally,” he adds.
“There are many factors driving the trend for tall buildings,” observes Kim, recalling: “Land scarcity, high land prices and urban density are sometimes pointed out as such, but it’s rather unlikely that these are the leading motives to develop tall buildings in Middle Eastern cities.
“Experiencing a fast developing economy can be cause for a greater demand for office and residential space, but that doesn’t necessarily explain why that has to be a tall building,” he continues.
“Being very visible objects in the urban landscape, tall buildings in the Middle East can be more likely explained for their modern and international appeal and the way skylines can embody strong, ambitious cities. Pride can also be quite a strong motive, especially when the commissioning party is characterised by strong individual leadership.
“History has shown that if you would like to make a point or create a presence, a tall building, and especially a super-tall one, is an interesting way to do it,” Kim adds.
Kim’s comments are echoed by Murat Tabanlioglu, of Turkish firm Tabanlioglu Architects, designers of Turkey’s highest tower, Sapphire; which this year made the top 20 tallest in the world, ranked 15th by CTBUH.
“Investors or governors all around the world desire to create a memorable building in their cities, to leave some symbol behind; in our century of high technology, this figure is usually a high-rise,” Tabanlioglu says.
“Construction has always been an indicator of economic activity and projection.
“Many cities in the Middle East become the showcase of this financial power, presenting brilliant samples of contemporary architecture.
“The ‘world’s tallest’ competition kind of shifted from North America to Asia and Middle East,” he adds.
How high?
Yet despite the trend being clear, continually raising the bar isn’t sustainable. When The Chrysler and Empire State buildings opened in New York in the 1930s the world was in awe.
At 318 and 381 metres respectively, today they don’t even make CTBUH’s top 50. Referred to as the ‘supertalls’, currently there are 50 buildings around the world which surpass the 300 metre mark; eight of these were completed last year, four of which are higher than 400 metres (see box).
Additionally, 66 buildings of 200 metres or higher were completed last year, breaking the previous record, set in 2007 when 48 such structures were completed.
According to the CTBUH, this represents a 40% change in the world’s tallest ten buildings in a single year; a feat which hasn’t happened since 1930, when America was leading a skyscraper revolution.
“Statistical research shows that in the course of time, buildings are growing taller,” says Kim.
“Based on technical and economic assumptions it’s easy to reason that there must be a cap on this, but so far there is no indication we have reached that point yet,” he adds, saying the next emerging trend is not just to build up, but to build out.
As with the Burj Khalifa and its surrounding Downtown area, the Kingdom Tower is planned to be surrounded by an entirely new city, which according to both Kim and Mills is the real money maker.
Kim cites the Linked Hybrid Complex in Beijing and Singapore’s Pinnacle@Duxton, both winners of CTBUH Best Tall Building awards, as prime examples of “the relationship tall buildings are establishing with their horizontal environment, and the social environments which are created”.
“I think we are witnessing the birth of a tall building type which doesn’t just scrape the sky. Perhaps more in common with the already familiar term groundscraper — as a building or podium that extends its horizontal connection with the ground — I see buildings that try to open up to the city on all levels.
“Maybe in the future we will call these buildings cityscrapers or urbanscrapers. Whatever their name will be, it is exciting to see that the tall building is again a frontrunner in the way we shape our cities.”
Mills agrees, explaining there is economic worth in breaking records.
“As they stand on their own you probably don’t make a great deal of money out of such towers, but when you blend that in with a development, as they have done with Burj development, it becomes the centre-piece of that area and you can charge a premium on the other properties, which helps recover the costs for that tower. That’s really the success story for Burj Khalifa,” he says.
On the other hand, there are practicalities to building at such heights which go beyond the commercial aspects.
“Structurally you can build as tall as you like. You have to have the foundations to allow you to do that and the space, as the taller the building the more space you have to have at the bottom to hold it there,” adds Mills who explains the Burj Khalifa’s foundations are expected to last around 300 years.
Tabanlioglu observes: “In the present age of enlightened ecological consciousness, architects are trying to make new connections between the design of living space and a much wider world than they have ever dealt with before.”
“We should question what these connections might be in relation to the urban construction. Skyscrapers are also an outcome of high population, but is it really necessary to get this high?“ he asks.
Extreme engineering
Record breaking, stunning structures don’t necessarily translate into practical developments where people can live and work. As Mills points out, a quick trip to the shop for a pint of milk isn’t quite the same when you live 600 metres off the ground.
When asked about the practicalities of building higher than the Burj, Tabanlioglu agrees, commenting: “I don’t think the intention is going to be ‘taller’ or ‘the tallest’, the new developments should be serving wider communities and promoting sustainable building forms extensively used by the public to help save natural resources and add value to the urban texture as well as the economy and betterment of people’s lives.”
Adding that a taste for the “extreme” among the younger generation will drive the popularity of the completed Kingdom Tower, he still warns that higher isn’t always better.
“Feasibility of a building is a crucial criterion; overbuilding, in height and quantity, may create financial and social problems, and dead cities like idle unmanned spaceship, so such decisions should be a part of precise planning,” he says.
The Burj Khalifa was one project where every possible outcome was considered; from balcony doors that automatically lock during high winds, to reinforced stair cases and alarms linked to the Civil Defense, the project is as safe as it is possible to be and every possible scenario was considered in its design.
“Put simply, a building twice as tall will probably give you four times as many headaches,” says Kim.
“Naturally the issue of structural stability and safety is one issue, but also practical issues, such as pumping concrete all the way up to the 180th floor will require creative and out of the box thinking as normal techniques of doing so will not be sufficient,” he adds.
Mills agrees, recalling how every day working on the Burj Khalifa was a test of the most innovative problem solving methods; trailing new and different techniques and methods as they were required.
The Burj Khalifa’s spire, which alone stands at almost the same height as the Eiffel Tower, is made from more than 4000 tons of structural steel, weighing so much it had to be constructed inside the building and lifted more than 200 metres using a hydraulic pump.
In order to pump concrete to the top of the structure, a range of plasticizers and retarders had to be used to prevent it from setting in the pipes. Concrete was pumped up continuously, and when no longer required, drained from the pumps into a reservoir on the ground, where it could be used in the surrounding developments.
It is due to such techniques being tried and tested in Dubai that the knowledge, and technology, now exists to reach even higher.
Since the first skyscraper was built in 1908, technology has developed at a rapid pace; so much so Mills predicts it may even be possible to find a solution to strengthen the current record holder’s foundations, prolonging its projected lifespan beyond the 300 years it currently stands at.
In addition to the solutions that made physical construction possible, a number of further solutions were required to make the finished project inhabitable.
“In the end, a tall buildings is designed to do what all buildings essentially do, which is offer shelter and provide a pleasant environment to live and work. When for example people experience motion sickness because of the way the building has been structured, it will be difficult to present these spaces as premium real estate; record breakers or otherwise,” warns Kim.
The developers behind the next potential record breakers will no doubt seek the expertise of those who have already achieved the ‘impossible’.
“It’s similar to the research that goes into a Formula 1 car and how the experiences that comes out of that can be applied to consumer automobiles,” says Kim.
“One of the very first things we would like to talk about to anybody in the countries where such developments are taking place, is to appreciate what the project is trying to achieve and recognise it is not a charity or a tower being built as a monument, but it is built to earn money,” asserts Mills, concluding: “The benefit and money that the
whole community receives when the tower starts being occupied is great.”
