In Riyadh, a Supertall Tower by HOK

The crystalline facade at the Capital Market Authority Tower in Riyadh, designed by HOK, plays many roles.

Symbolically, it references crystals found in wadis – the dry ravines of the Saudi Arabian desert. “It may be crafted by men, but it’s rooted in the land and the geological formations of the region,” says Roger Soto, design principal at HOK

Its transparency creates an open grid and provides access to natural light within the office tower. The 76-story tower, anchor at the new King Abdullah Financial District, is clad in a glass unitized curtain wall system, triple glazed. Attached to it is a system of catwalks at every level, with vertical, diagonal sunshades.

“The idea was to create a response to climate control and maintain it in a regulated way,” he says. “In Riyadh there’s a constant problem with dust and dust storms at certain times of the year so, buildings get dirty quickly. The catwalks are a means of cleaning the glass and changing out the panels.”

Then there’s the status it’s designed to deliver. It’s not just the tallest building in Riyadh; there is symbolism involved too. “It expresses their desire to be a global financial center,” he says.

As if juggling the facade’s performance weren’t enough, there were also the constraints inherent in the site, which was neither square nor rectangular, but trapezoidal. “We had to fit to it tightly, and fit it into a plaza,” he says.

Working with in collaboration with the Saudi Arabian firm Omrania & Associates, the architects aligned the building to a perimeter road, coordinating it with underground connectors at the lower levels, with underground parking and pedestrian bridges.

“All are incorporated into the site, plus all the regulations about how tall the tower should be,” he says. “In that sense it was very constraining and some of the most proscriptive regulations I’ve had to work with.”

When it’s finished in 2017, it will stand at 385 meters tall, its top third reserved for the Capital Market Authority, and the rest for other businesses. Its hexagonal-shaped plan tapers inward and outward, providing floor plates that range from 26,900 sq. ft. to 28,000 sq. ft., for flexibility in spaces.

And it’s not the only building under construction. “It’s complicated because they’re building the whole financial district at the same time – about 40 million square feet,” he says.

But this supertall tower’s at the heart of it all.

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