ABU DHABI expects to merit an entry in the Guinness World Records next year for being home to the world’s most inclined high-rise. This is when the iconic Capital Gate, now taking shape adjacent to the Abu Dhabi National Exhibition Centre (Adnec), will see final completion.

Construction work on the distinctive tower – designed by the prestigious global architectural practice of RMJM Architects – is progressing on schedule despite the complexities of creating such a structure, according to its developer Abu Dhabi National Exhibitions Company.
The external face of the Capital Gate tower, part of the Abu Dhabi National Exhibition Centre (Adnec) development, will be complete in the last quarter of this year.
The 35-storey and 160-m-high tower leans 18 degrees to the west and forms the ‘gateway to Abu Dhabi’.
Capital Gate forms the centrepiece of the Capital Centre development, a Dh8-billion ($2.18 billion) business and residential micro city being constructed around the thriving Abu Dhabi National Exhibition Centre.
Capital Gate’s floor plates are stacked vertically up to the 10th level. But from there on to level 27, they stagger over each other by 800 to 1,400 mm per floor and then reducing from 900 mm to 300 mm. The central core is vertical.
“The building also rotates with height. The result is that it looks different from every direction,” RMJM associate director Tony Archibold  tells Gulf Construction.
“To deliver this effect, the cladding system had to be tailored floor by floor. To help make it work, a reinforced steel diagrid (external exo-skeleton) comprising 728 separate diamond-shaped elements has been used for the first time in the Middle East. The diagrid alone has required 7,000 tonnes of structural steel – the total used in the entire Capital Gate building is more than 20,000 tonnes, one of the highest figures for a tower in the Gulf where reinforced concrete is conventionally used to give buildings strength,” he explains.
The steel diagrid sits above an extensive distribution of 490 piles that have been drilled 30 m underground to accommodate the gravitational, wind and seismic pressures.
Currently, the core of the tower is at floor 30, the steelwork is at floor 26 and the glass exterior is at floor 18. Recently, a gigantic internal atrium, including the swimming pool and tea lounge, was suspended on levels 17 and 18 – the halfway point of the 160-m-high tower.
Construction of the steelwork for the tea-lounge on floor 17 has already begun, and the scaffolding has been prepared to support the construction of the splash-down, which will be constructed from the 17th floor downwards and will ‘wash over’ the existing roof of the Adnec stadium.
When complete in the second half of 2010, the Capital Gate will lean an astonishing 18 degrees westward, 14 degrees more than the famous Leaning Tower of Pisa. By installing a huge number of steel struts, engineers have realised Adnec’s and the project architect’s (RMJM) vision of the atrium – creating a cantilevered tea lounge and swimming pool suspended 80 m above the ground.
In the final stages, a helipad will be added to the roof of the building as the final feature on this magnificent building.
Commenting on the challenges on the project, Archibold says: “This is one of the most technically challenging projects under construction in the world at the moment. It is a truly original design, aspects of which, such as the pre-cambered core, have never been attempted before. It is also the first building in Abu Dhabi to use the diagrid technique.
“There is nothing standard about Capital Gate. Each room is different, each pane of glazing is different and every angle is different. It was designed to provide no symmetry so that it inspires those inside and outside.
“Needless to say, this provides technical challenges that are being overcome through teamwork such as our partnering programme. This is a technique we have employed on all of our developments. It is where all lead contractors working on a project literally sit together in one location. Architect sits next to project manager, who sits next to quantity surveyor, who sits next to building contractor – the objective is to remove confrontation and create a single team mentality with one single goal – to get the project completed.”
For sustainability, the use of a double-glazed façade will help achieve greater energy efficiency. Strategically-positioned air inlets will draw air from outside into the open space between the skins. This air will circulate and rise within the façade as it finds its way around to the other side of the building where it is expelled. The result will be a thermal cushion between inside and outside, meaning that the structural diagrid will be held at a constant temperature.

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The reflectivity of the outer skin of glass will prevent the sun’s ultraviolet rays penetrating.
The project has been developed as a tribute to the late president of the UAE, Sheikh Zayed bin Sultan Al Nahyan, by integrating the Grandstand, a building which was used by him to view parades, into Capital Gate through an innovative sweeping canopy roof, according to Adnec.
As the canopy sweeps up from the Grandstand, it will use a solar shading device. The canopy will twist around the building towards the south to shield Capital Gate as much as possible from direct light. Perforated metal sheeting will allow for the views to be maintained whilst reflecting the sun’s harmful rays.
The tower will offer 20,000 sq m office space from level one to 17. It will house Abu Dhabi’s first Hyatt hotel – Hyatt at Capital Centre, a presidential-style luxury five-star hotel which will offer 189 hotel rooms and also host a variety of food and beverage outlets as well as a spa and fitness centre to Adnec visitors and exhibitors as well as international business and leisure travellers. The hotel sky lobby will be located on level 18.
Due to the unique curving shape of the building, each room in Hyatt will have different shape and orientation. The interiors of the hotel rooms – ranging from 92 to 230 sq m, have been individually designed. A sleek contemporary design blending dark woods and natural elements complement the refined ambiance of the hotel.
Capital Gate is set to enter Guinness World Records as ‘world’s most inclined tower’ with Adnec and RMJM having submitted a joint application to the Guinness Book of Records to recognise the tower as the “most inclined in the world”.