In profile: Capital Market Authority Tower by HOK
Roger Soto, HOK design principal, detailed the challenges of building 'super-tall' in the Middle East during New York's Council on Tall Buildings and Urban Habitat conference
The anchor of the new King Abdullah Financial District, the Capital Market Authority Tower by HOK soars 385m above the surrounding Riyadh cityscape and is the tallest of the five structures making up the plaza.
The overall design of the faceted crystalline structure responds to the vision set forth by the developer of the district, the Al Ra’idah Investment Company. With an ambitious goal of LEED Gold certification, HOK designed the tower in collaboration with Saudi Arabian firm Omrania & Associates.
Roger Soto, HOK design principal, was a featured presenter at the annual international conference of the Council on Tall Buildings and Urban Habitat which was held the Grand Hyatt in New York and described how the tower was designed.
The faceted crystalline structure will have 73 occupied floors and a gross floor area of 182,137m2
The architects said: “Harsh environmental conditions in Saudi Arabia pose unique challenges to the construction of supertall buildings. Intense solar radiation increases heat gain and the accumulation of fine-grain sand clings to building surfaces.”
In his presentation, Soto described how the team overcame these challenges by creating a high-performance enclosure that incorporates solar shading, photovoltaic solar collection, facade lighting and an innovative facade access system. This integrated solution reinforces the overall building design and geometry while minimising solar gain and internal cooling loads, reducing HVAC requirements and reclaiming electrical energy.
The major components of the high-performance enclosure system include triple-glazed insulated glass units; unitized type glass curtain wall; a horizontal gantry, or catwalk, located on each floor; an array of angled glass fins connected to the gantry for shading; and a photovoltaic array located in the crown of the building.
The building’s main structural skeleton comprises a central core, perimeter columns, composite floors, roof crown and a continuous raft foundation. The central core is made of cast in-situ reinforced concrete walls interlinked in a hexagonal-shaped pattern by coupling shear beams. The form tapers inward and outward as it rises.
“Together with its dynamic facade, the iconic geometry of the building contributes to a highly functional yet strikingly originally form on Riyadh’s skyline,” said the architects.
The modular plan creates a highly efficient interior environment with clear-span floor plates that maintain their flexibility and adaptability across every level of the structure. Combining public circulation and private amenity space, the podium structure at the base of the tower includes an auditorium, cafeteria and two-story atrium.