About Al Bidda Tower
Located at a prominent location in the heart of the Dafna Area overlooking the corniche, Al Bidda Tower’s dramatic twisting face makes it unique amongst the other towers of the Doha skyline. The rounded triangular shaped floor plan of the tower has been conceptualized such that it is larger in floor area at the top floor than at its base, giving an elegant profile. This is enhanced by the cut roof shape under which there is a five-story open atrium. The tower is clad in an unconventional diagonal curtain wall that accommodates the progressively enlarging floor plate, as well as the shift of 60 degrees at the apex of the rounded triangular shaped roof.
The resulting multi-faced glass reflects the sunlight and nearby water during the day and artificial interior light during the night in various directions, giving the façade a jewel like luster. Every floor is unique, both in plate size and geometric location. In order to maximize rentable floor area there are no internal columns. The external columns twist with the building, and thus slope in two directions. To resist the resulting lateral loads, a braced steel diagrid is utilized, reflecting the triangular curtain wall system.
In order to reduce the effects of increased loading to the steel bracing in the diagrid, the installation of the bracing into the external frame was delayed by 56 days after concrete casting. During this period it was estimated that approximately 45% of the total expected creep and axial shortening would have occurred, thereby reducing the expected increase in loading to the diagrid steel bracing.
Being located in Doha where temperatures and solar gain in summer can be high, and being totally clad in a glass curtain wall, posed some challenges in terms of ensuring occupant comfort and air conditioning efficiencies. The thermal performance of the façade had a significant impact on building energy consumption. The thermal performance of the framing system also had a considerable effect on the overall performance of the façade, and the combined thermal effects of the frame and glazing were accurately calculated to determine the total thermal performance of the system. Double glazing incorporating low-E glass was adopted following extensive testing. The façade work was made more complicated by the building geometry, where every triangular panel is different.