In pictures: Cleaning the most difficult windows in Middle East

Burj Khalifa, Dubai Height 828 metres, Emaar’s Burj Khalifa is the tallest building in the world. The Burj’s complicated shape makes it one of the most challenging buildings a window cleaner is ever likely to face. Designed to incorporate traditional Islamic patterns into a tri-petalled flower resembling a desert rose, the problem for window cleaners is to get around the glass curves in order to clean. The building is cleaned using both abseilers and cleaners standing on elevated gondolas. CoxGomyl has set up 18 gondolas to maintain the building including the highest building maintenance unit in the world working at a height of 715 metres. Three sets of machines – stationed at levels 40, 73 and 109 – are mounted on horizontal tracks, which means they can travel across the facade.

Capital Gate, Adnec headquarters, Abu Dhabi- Height 160 metres Known as Abu Dhabi’s “leaning tower”, this 53,100-square-metre building leans four times as steeply as the Leaning Tower of Pisa in Italy. Although the building has sets of gondolas built into the design to clean its exterior, Grako’s Alain El Tawil says abseilers are used instead because the unusual building’s lean makes it hard for ordinary machinery to reach the windows. Abseilers can also work in bigger teams, making the cleaning process quicker. To reach the underside, each window cleaner must first descend on a rope then use suction pads to overcome gravity and get to those hard-to-clean surfaces. The bottom of the building is cleaned using a device on wheels with a mechanically raised and lowered platform and high-pressure jets of water.

Aldar headquarters building, Abu Dhabi - Height 110 metres
The world’s first and only circular tower, Aldar’s 23-storey, 666,000 square feet head-office building requires some of the most complicated and advanced cleaning and maintenance equipment in the world to scale it. “The building shape is quite interesting here as it is round in the one plane and oval if you look at it from the side,” says Cox Gomyl’s Theo van der Linde. “The BMU [building maintenance unit] was designed to cover the whole building, therefore it can travel all the way around the building from one side to the other side in order to offer access to all the facade. “This BMU has three cradles to carry out the cleaning of the facade. We have two cradles on either [circular] side of the building. Therefore, two teams can work simultaneously.”

Aspire Zone, Doha Sports City, Qatar - Height 300 metres for the tower, making it the country’s tallest The futuristic tower, which makes up the centrepiece of the 250-hectare Aspire Zone, was designed to resemble a torch during the 2006 Asian Games. It also has a special video screen woven into a wire mesh measuring more than 1,000 square metres. The rest of the complex includes a mosque, sports dome and football stadium. The Australian company UGL is charged with facilities management at the site, which requires cleaning from ground level using a telescopic pole and abseiling down the tower to clean the facade by hand. “We need to complete six cleaning cycles per year and each cycle comprises of 60 calendar days with a team of six facade-cleaning specialists,” says Mark Cooke, UGL’s general manager for business operations in the Middle East.