In Oklahoma City, the seemingly improbable Legends Tower has passed a major hurdle towards its realization.

On June 4, the city council approved in an eight-to-one vote the rezoning of the three-acre development site, dubbed Boardwalk at Bricktown, of which the 1,907-foot-tall tower is the most conspicuous component. The skyscraper, if built, will be the tallest in the United States, a distinction currently held by One World Trade Center in Lower Manhattan. It would also be the fifth-tallest in the world, trailing behemoths such as Dubai’s Burj Khalifa and Merdeka 118 in Kuala Lumpur.

Boardwalk at Bricktown will span more than three acres, and its podium would include a host of retail and entertainment establishments. Image courtesy AO

Orange County, California-based Architects Orange (AO), a firm with expertise in entertainment districts, is leading the design of the 5 million-square-foot mixed-use development, which will include a retail-and-entertainment podium, and three other 345-foot-tall towers. The towers would house some 900 hotel rooms and 1,776 residential units, approximately doubling the amount of housing in downtown Oklahoma City. As reported by RECORD in March, the $1.2 billion project has been in the works for at least two years—and, according to Boardwalk at Bricktown’s developer Scot Matteson, founder and managing partner of Matteson Capital and Centurion Partners, it is fully financed.

The Legends Tower would stand out in the relatively muted Oklahoma City skyline. Image courtesy AO

Naysayers abound for the Legends Tower. Many question the economics of a supertall in America’s 20th-largest city, and the wisdom of building such a lanky edifice in the often-windblown Tornado Alley. For the design team, these concerns are misplaced, if not misguided. “Oklahoma City is the sixth-fastest growing city in the country right now, and if you look at a map, this property is dead center of substantial new developments, like the city’s new convention center; the planned $900 million downtown arena for the Oklahoma City Thunder and a 10,000-seat soccer stadium for the Energy FC, and others,” says AO managing partner Rob Budetti. “The city has invested a lot of money into this entertainment district, and Boardwalk at Bricktown is another piece of that puzzle.”

Although there is plenty of work to be done before the Legends Tower’s design is finalized, determining the structure is fairly straightforward, according to Ola Johansson, senior principal at Thornton Tomasetti, which is serving as the project’s structural consultant.

The structural system being developed by Thornton Tomasetti will likely consist of a concrete-and-steel building core, outrigger concrete columns and steel trusses, and post-tensioned concrete floor framing. Image courtesy Thornton Tomasetti

“Thornton Tomasetti has completed a number of skyscrapers in areas with very high winds, like Taipei 101 (1,667 feet) and Shanghai Tower (2,073 feet). It’s really just a matter of understanding wind forces, through, for example, wind tunnel analysis, and designing for them,” Johansson explains. “Controlling the movement of the tower, for occupant comfort, is the greater challenge.” To that end, the tower will likely be built atop a concrete mat foundation grounded into the earth by a grid of drilled piers, with a central core of high-strength concrete and reinforcing steel, that, in turn, reaches out to a system of perimeter columns with outrigger steel braces—post-tensioned concrete floor framing fills the gaps in between. The engineering team is still studying the efficacy of adding a mass damper to further reduce projected building sway, and, in terms of tornado events, the curtain wall can be strengthened at the lower levels against flying debris.

The project is still awaiting approval for its luminous LED display, which will also ascend the tower's curtain wall system. Image courtesy AO

With approval in hand, the design team is aiming to break ground before the end of the year on the larger development; work on the tower itself will likely only commence once two of the shorter towers planned for the site are at least 50 percent leased. And while the site is now rezoned to permit the incredible height of the Legends Tower, Boardwalk at Bricktown still requires city council approval for the proposed luminous LED display at the building podium, which, according to the design team, could be embedded within the tower’s curtain wall mullions, like Burj Khalifa.