“Horizontal Sky at Khor Dubai Wharfage”, DUBAI, UAEAll images and information courtesy of Coop Himmelb(l)au; image © Armin Hess, ISOCHROM
Coop Himmelb(l)au architects have provided us with the third project of their design trilogy for the Dubai creek area.
Horizontal Sky is a new concept for spatial organization and building form in the competitive skyline of Dubai.
The common vertical tower is redefined as a long and flowing multifunctional horizontal bar of public and private functions flowing and intertwining with three vertical cores corresponding to the three piers at Khor Dubai.
The building is like a sculpted high-rise turned on its side and lifted into the sky.
Horizontal Sky’s paradigmatic concept creates an entirely new and unmistakable icon on the skyline and provides a never before experienced urban condition that is both reflective of and connected to the position on the Khor Dubai waterfront. The iconographic quality and unique functional, spatial and view conditions will ensure that the new building becomes the most well known destination in Dubai and the U.A.E.
Located at Dubai city’s most prominent waterfront the new tower complex at Khor Dubai will be a recognizable architectural landmark and establish the new face along Khor Dubai.
Urban Design Strategy
The new tower complex augments the cultural life of the Wharfage with new commercial and public spaces and will improve the urban quality of the city for business people and visitors.
Thus our proposal is a unified composition of three lifted towers linked by public zones and merged into one hybrid form floating above the Wharfage. The resulting hybrid “vertical city” creates tension with the surrounding urban structure, mediating and connecting the urban fabric and flows and establishing a new urban model for this location in Dubai.
As a contemporary cultural business hub the new tower complex becomes a major tourist destination. A museum and a theatre enhance the basic hotel and office program. Public areas on the top of the building are the main attraction of the complex for tourists and tenants. A 540 meter-long recreation area houses the world’s longest indoor pool and bar. An indoor shopping promenade connects one side of the building to the other and takes advantage of the building’s height and form to provide spectacular views for the visitors of the city in all directions.
image © Armin Hess, ISOCHROM
Circulation And Entrances
Tenants and visitors arrive from the car park facility, which is located at the far corner north of the Baniyas Road, to the three main lobbies of the complex located at the point of each of the three piers by cable car or by foot via an expressive curving causeway with sweeping views of the Dubai Harbor. From all three lobbies public elevators connect the entrance floor individually with the commercial, offices or hotel room floors. Public access is only provided to the shopping passage and recreation area as well as the museum and theatre while business people and hotel guests have the possibility to get to the public areas from each floor by their own elevators controlled by a key card system.
The drop off point for the Hotel above the first pier is connected by a bridge to the bank in the north next to the Chamber of Commerce. On the Marina on the tip of the pier a welcome area for guests that arrive per boat is provided. Elevators connect the arrival levels with the Hotel lobby.
From the elegant lobby space of the Hotel in the lower part of the cloud-shaped “Horizontal Sky”, separate hotel guest elevators connect directly with the lower hotel room levels while further exclusive elevators are reserved for the guests of the suite levels. All elevators connect the hotel floors with the shopping and recreation areas on the top floors and access control is achieved by means of key cards. Exiting the hotel elevators, guests move along a walkway framing the atrium space along the north façade of the building providing spectacular views to all guests on their way to their rooms. The majority of hotel rooms face the river, and several room sizes can be achieved within the structural grid of the building offering a flexible layout to suit the wishes of various Hotel Operators.
The two office lobbies above the second and third piers are well connected to the office levels. Each floor is zoned in office areas that are divided into private and semi-public zones, circulation areas and atrium spaces facing the North façade. Each office area can be programmed individually by the users. Office layout’s can accommodate group- or single offices linked to meeting areas and common zones.
image © Armin Hess, ISOCHROM
In the first step the three concrete cores are erected. The first two spans of the steel structure that protrude from both sides of the cores are then attached to the concrete structure. To stabilize these standalone elements against torsional forces, the cores are joined to each other by the upper part of the lattice girder, utilizing the cantilever method of construction. From this the remaining steel structure is assembled from top to bottom.
The bridge structure serves as a supporting system during the further construction process. E.g. scaffoldings for the assembly of the ramp structure are added.
All floor space is located in the large ‘bridge’ building that spans between the three highrise concrete cores. The double-span beam spans over a distance of about 220m each and is cantilevering at its ends. In longitudinal direction the form of the building describes a smooth curve, adapted to the moment at the support.
To assure sufficient stiffness of the bridge building a steel mega-structure is proposed. This mega-structure consists of two lattice frameworks connected with structure of the slabs in between. The slabs are implemented as composite construction and horizontally stiffened by diagonal ties. The beam acts as a large box girder; thus torsional stiffness is achieved. The structure is optimized for the steel stress and the vertical deflection is limited to l/300.
The three cores are each 80 meters high and have a dimension of 12 x 12 meters. The horizontal forces are carried through these cores into the ground.
The ramp structure is positioned under the bridge. Its cross section measures 8 x 10m and resists the dynamical load of the cable car traffic.
In longitudinal direction the ramp building is a stiff torsional box framework.
The supporting of the ramp is realized by tension members connected to the top of the main building. Compression members are connected to the bottom of the main building. This support system realizes not only a vertical and horizontal support, but also avoids a torsional rotation and the slim cross section due to the span lengths can be realized.
image © Armin Hess, ISOCHROM
Since all loads are carried through the cores, a pile foundation is proposed below them.
Environmental, Energy And Building Services Concepts
Strategies employing the form of the building to assist natural ventilation together with the use of renewable energy sources (wind and solar power) assure an energy efficient design and reduce energy consumption and reliance on fossil fuel energy sources.
Excessive wind pressures are reduced via an additional outer metal façade construction, which is a sun blocker as well as a solar screen formed in a pattern optimized to orientation. The density of these varies according to orientation and tilt angle, thus creating a visually interesting pattern in the building skin as well as in the roof surface. Dubai enjoys some of the best climatic conditions in the world for the generation of electricity employing photovoltaic cells.
The building design also enables wind energy to be captured and employed via a wind generation plant to generate renewable electrical energy.
Ventilators are integrated in the façade on the top. The total building length of 540 meters is used to generate energy.
Alternative Energy Sources
Biomass or possibly gas fueled combined heat and power generators provide the building with both heat and electrical power. This solution has both ecological and economic advantages compared to more conventional alternatives (c. 60% less CO2 emissions), and also provides a major advantage with regard to security of supply. In warm weather the heat is used to drive an absorption chiller that supplies chilled water to cool the building.
Plant rooms for technical equipment are located as shown in the diagrams and are connected via vertical shafts and risers to the individual floors to provide an efficient technical infrastructure. An integrated security system is provided including CCTV (closed circuit television) surveillance of public areas, full function access control at selected entrances and lifts and central monitoring equipment within a main lobby security/ reception desk. A complete Building Management System (BMS) is provided consisting of multiple Direct Digital Control (DDC) data processing outstations and a central management system.
image © Armin Hess, ISOCHROM
PLANNING COOP HIMMELB(L)AU
Wolf D. Prix / W. Dreihbolz & Partner ZT GmbH
DESIGN PRINCIPAL, CEO Wolf D. Prix
PROJECT PARTNER Michael Volk
PROJECT ARCHITECT Andrea Graser
PROJECT COORDINATOR Pete Rose
DESIGN ARCHITECT Andrea Graser, Victoria Coaloa
PROJECT TEAM Vincenzo Possenti, Juong Park, Anja Sorger, Giuseppe Zagaria
Daniela Comito, Chih-Bin Tseng
PHOTOGRAPHY Markus Pillhofer
3D VISUALIZATION Armin Hess/ ISOCHROM
STRUCTURAL ENGENEERING B+G Ingenieure, Bollinger und Grohman GmbH, Frankfurt, Germany
CLIENT/ WBW AUSLOBER MIZIN – A member of TATWEER, Dubai, United Arab Emirates
SITE AREA 3x 2.800 m² (piers)
FLOOR AREA 70.000 m²
1. PHASE Dec 2007
2. PHASE Feb 2008