The Souk, Abu Dhabi Central Market, by Foster & Partners
An opening roof allows rain to fall on an internal tiled square in this ambitious modern reinterpretation of the traditional Middle Eastern souk.
Architect Foster & Partners
Location Khalifa Street, Abu Dhabi, UAE
Completed December 2010
The request to design a roof that opens when it rains seems an odd one. However, this movable section of flat roof to a new retail building is in Abu Dhabi, one of the hottest and driest cities in the world. When the rain makes one of its rare appearances it is welcomed, and the open aluminium blades allow it to land on an internal waterproof, tiled public square directly below.
Foster & Partners’ three-storey Souk is part of the architect’s Central Market development, an ambitious, mixed-use 4ha scheme still under construction and dominated by three high-rise towers of varying height and bulk.
The Souk replaces a single-storey concrete framed retail building built in the 1970s, but burnt down in 2004. The new building is a rectangular structure with a floor area of more than 27,000sq m and six floors of underground parking. Its design is a departure from the modern glitzy shopping malls often found in Arab cities and is instead a modern reinterpretation of the traditional Middle Eastern souk. It is devoted to small shops of traditional crafts and local produce, with display areas outside the units, in an interior of dappled sunlight with a changing rhythm of squares, courtyards and alleys.
Like the building it replaced, the Souk has an in-situ concrete structural frame, but its external envelope is more daring, using glass-fibre reinforced concrete (GRC) screens inspired by Arabesque patterns and art. The cladding is a reddish colour to match the colour of the sand in the UAE’s Liwa Desert, and was made by a local workforce that used a traditional process of moulds to make the screens rather than mechanised western processes. The GRC screens are hung from a curtain walling system that runs around the full circumference of the building.
The Souk is laid following a tartan grid pattern forming a network of retail and circulation spaces with one circulation shaft cutting vertically through the building to provide access from the basement car parks to the upper levels.
The vertical shaft is enclosed at roof level with a double-glazed rooflight. Several more rooflights are arranged over the wider circulation areas to draw in daylight into the interior.
Most of the flat roof, with the exception of the opening section and a number of sunken terraces, is landscaped to create a vast public space. The roof is laid with a single ply membrane and then fitted with paving slabs or screed and plant boxes. During the cooler months, shoppers can sit on the landscaped roof enjoying their shisha pipes in open air cafés.
Opening shading system
In the north-east quadrant of the Souk’s roof an area measuring 8.4m x 16.8m opens and closes depending on the weather conditions. In summer, when temperatures can often soar to 50˚C, the roof closes to keep out the sun, but in winter, when temperatures are a pleasant 18˚C the roof is left open helping to ventilate the interior.
“Following the concept for the eastern market place with patterns and geometric grids and their subdivision,” says Foster’s partner Stuart Latham. “We used these themes to enclose a public square that could vary in its character through its response to the seasons.
“We approached [specialist engineer] Hoberman Associates to develop a technical solution for an opening roof.”
The main supporting structure to the opening and closing system is composed of mild steel that is made up of universal beam sections 720mm in depth that are bolted together.
The opening roof is then divided into eight bays, each 4.2m x 4.2m. Each of these is further split into nine apertures by a fixed aluminium profile welded together. Within each bay there are seven bronze coloured 160mm-wide aluminium blades of different lengths that lie horizontally, with each blade held into the frame slightly higher than the other.
As the roof opens, the blades slide back under each other in a smooth motion into the supporting frame and profile, forming a stepped pattern. The opening and closing motion is driven by two hydraulic arms that sit opposite each other within the frame.
The roof takes exactly 24 seconds to fully open or close and is controlled from a building management system. When fully open, only the steel frame and aluminium profile are visible and create a space for the parking position of the blades.
Adjacent to the opening roof is a 2.5m-wide solid roof system which houses the building services and is made from insulated aluminium panels. The opening roof and the solid roof system are surrounded by 2.8m-wide glazed rooflights, divided into 900mm square elements which can be opened for ventilation.
Directly below the roof is a public square offering a lofty double-height space. The roof is supported here by six 15m-tall steel columns of 508mm diameter welded together and spaced 8.4m apart.
Client: Aldar Properties PJSC, Architect: Foster & Partners, Collaborating architect: Planar, Main contractor: Mushrif National Construction, Project manager: WS Atkins, Structural engineer: Halvorson & Partners, MEP engineer: BDSP Partnership, Cladding specialist contractor: Shenyang Yuanda, Cost consultant: EC Harris International, Fire consultant: Exova Warrington Fire, Facade consultant: Arup