Burj Dubai

Meraas dreams of a city in the sky

Last Updated: September 19. 2008 12:30AM UAE / September 18. 2008 8:30PM GMT Demolition work has begun in the Satwa neighbourhood of Dubai for Jumeirah Garden City, but Meraas has not yet specified which of three building plans it will pursue. Pawan Singh / The National It may seem like a tall order, but a Dubai developer is considering building a tower three times the height of the Burj Dubai.

Three designs have been drawn up for the planned Jumeirah Garden City project, with the most breathtaking being a 2.4km-high edifice called the Dubai City Tower. Renderings of the Dubai City Tower show six separate buildings twisting into a single structure dubbed a “vertical city”, capped by a 400-metre “energy-producing spire”.

“The Dubai City Tower pushes every edge of building design,” says the design proposal, which is circulating on the internet.

“For centuries man has pushed construction toward the heavens. The sheer scale of this project will focus the world’s eye towards the city of Dubai, but it will be the tower’s design and image that will preserve Dubai City Tower’s grandeur into the future.”

Meraas, the property developer and private equity fund of Sheikh Mohammed bin Rashid, Vice President of the UAE and Ruler of Dubai, is behind the project, according to a consultant for the company and a developer familiar with the plans.

The Dubai City Tower would dwarf the Burj Dubai, which reached 688 metres earlier this month. Emaar, the developer of the Burj Dubai, has kept the final height secret in part to prevent other developers from announcing taller projects.

The design prospectus for the Dubai City Tower, which does not list its developer or architect, shows the tower looming over the waterfront, near a marina.

It would have 400 storeys with each set of 100 storeys forming a “neighbourhood” and a Sky Plaza operating as a “town centre”. A vertical bullet train would ferry people from one “neighbourhood” to another.

The building would be fitted with solar panels and wind turbines, and biospheres that double as recreational parks and water purification centres.

Carol Willis, the director of the Skyscraper Museum in New York and a professor of urban studies at Columbia University, said the project appeared “buildable in technical terms” but economically difficult to justify.

Alastair Collins, of the international Council on Tall Buildings and Urban Habitat, said that height was the easy part with skyscrapers.

“The hardest part is the servicing of the height: the transportation, power, water and waste disposal,” he said, adding that such a tower would also produce swarms of traffic.

Another of the plans for the Jumeirah Garden City project includes designs for a building called the Atrium City Towers, which would incorporate three tall towers and was designed by architects Adrian Smith and Gordon Gill. Mr Smith also designed the Burj Dubai.

A spokesman for Meraas declined to comment on the designs, but said the company would reveal its plans at Cityscape Dubai on Oct 6. An advertisement for Meraas on the Cityscape website hints at a design similar to the Atrium project.

“They are seeking to create a standout building in that location, which is otherwise going to be really low-level,” the consultant said. “It will have the best quality hotels and commercial space in the heart of what is going to be a predominantly residential area with gardens.”

Meraas was created in 2007 and gained attention this year when it joined a coalition of investors that financed Boston Properties’ purchase of the General Motors building in New York for US$2.8 billion (Dh10.28bn). It was the most expensive office building sale in American history.

Jumeirah Garden City will be located in two districts, Satwa and Al Wasl, that are being razed to make way for the new development. The project includes a canal system and several iconic buildings.

“Sheikh Mohammed likes competition,” a consultant familiar with the company said. “He wants to add another layer to the other government-backed developers to challenge Sama, DP World and Nakheel.”

The company has also been hiring veterans in the Dubai market, including Binod Shankar, the former chief financial officer of Dubai Waterfront Corporation; Rashid Doleh, the former chief executive of Emaar Malls Group; and Vivek Rao, the former head of finance at Tamweel.

A mile-high tower is planned by Kingdom Holdings for Jeddah in Saudi Arabia and Kuwait also has a 1km tower in the works. Nakheel, another Dubai developer, is expected to announce a tower to rise higher than 1km in Al Burj, according to published reports.

The amount of decrease is governed by the dry adiabatic lapse rate. The reason for this decrease is as follows. When a parcel of air rises, it expands, because the pressure is lower at higher altitudes. As the air parcel expands, it pushes on the air around it, doing work; but generally it does not gain heat in exchange from its environment, because its thermal conductivity is low (such a process is called adiabatic). Since the parcel does work and gains no heat, it loses energy, and so its temperature decreases.

The formula is the following:
dT/dz = -9.8 C/Km which means approximately 1 degree Celsius drop each 100 meters of height.

However the above calculation is valid for dry atmosphere. In dubai, though sometimes in the winter it really gets dry - especially after heavy rain showers, the usual case is near 100% humidity. In this case we use the saturated adiabatic lapse rate. To save your time, here is the difference:
dT/dz = -6.5 C/Km which means 0.65 degree Celsius drop each 100 meters

In the case of Burj Dubai, at 819, the drop in temperature will be at 6-8 degrees.