This is one in a series of blog posts covering the intelligent, functional, and sustainable features of the Capital Market Authority (CMA) building, an 80-story class-A office skyscraper designed as a joint venture by Omrania and HOK, currently under construction, which establishes a new architectural and engineering benchmark for Riyadh while transforming the city’s skyline.
Rising from the heart of the King Abdullah Financial District — for which Omrania also served as design adviser — the CMA tower is visually distinguished by its sharp-faceted, articulated profile. Yet its most exciting features are its efficient and sustainable systems, starting with the high-performance enclosure system incorporating solar shading, photovoltaic (PV) solar energy collection, and integrated facade cleaning, via the following elements:
- A triple-glazed IGU (insulated glass unit), unitized-type glass curtain wall, which mitigates solar heat gain and reduces the cooling load.
- A horizontal catwalk made of coated aluminum, located externally at each floor, serving at once as an external shading device and part of the façade maintenance system.
- An array of 400-millimeter-deep glass fins with an offset frit pattern arranged diagonally across the building facade, for shading. The position and angle of the fins, connected to the catwalk, are optimized to account for solar tracking, reducing direct light exposure while enabling views and transmitting a respectable 35% of visible light.
- A PV farm in the tower’s crown, generating 300,000 kilowatt hours annually.
- An innovative building-maintenance system integrated with the curtain wall. Three platforms suspended from the tower roof are guided up and down the facade (which is not vertical), using adjustable arms to attach to the catwalk/shading devices at each level. A monorail track along the underside of each catwalk allows workers to easily connect a retractable lanyard to their safety harness and dismount onto the catwalk below. There, they find a cart equipped with cleaning supplies that rolls securely along tracks at the catwalk level. This system allows the tower’s exterior to be cleaned 15 times per year, compared with only four times per year using a conventional suspended-gantry system without catwalks — very important in a climate where windblown sand quickly accumulates on building surfaces. The system is also designed to facilitate replacement of the facade IGUs.
The high-performance envelope design and integrated facade-access system of the CMA tower represents a unique and integral solution to the challenges associated with facade design for super-tall structures in Riyadh and elsewhere in the region.