On the Las Vegas Strip, the Athletics’ new ballpark is taking shape as something far removed from a conventional stadium. Its five overlapping roof forms, inspired by baseball pennants, give the building the appearance of a giant armadillo. But beneath that expressive geometry is a carefully engineered steel system designed to achieve something much more difficult: a vast, column-free roof over 33,000 seats.
Designed by Bjarke Ingels Group (BIG) with HNTB and structural engineering by Thornton Tomasetti, the ballpark’s defining roof is supported by freestanding steel arch trusses spanning nearly 700 feet across the playing field. Once complete, the roof structure will rise approximately 290 feet above the field.
The five curved roof surfaces are more than an architectural gesture. Their overlapping arrangement is intended to respond to Las Vegas’ desert climate, limiting direct sunlight while allowing softer northern daylight into the stadium. The steel structure therefore becomes part of both the architectural expression and the environmental strategy.
The project’s steel application is already visible on site. In June 2026, crews lifted the first 200-ton roof truss segment into position. By August, the fifth and final steel segment of the second roof truss arch had been installed, completing an arch spanning nearly 700 feet.
Steel also works alongside another remarkable structural system at the outfield: a cable-net glass façade designed to create expansive views towards the Las Vegas Strip. Thornton Tomasetti is responsible for structural and construction engineering, façade engineering, connection detailing, waterproofing and façade access.
Scheduled to open for the 2028 baseball season, the ballpark offers a compelling lesson in structural steel: sometimes the most expressive architecture begins with the simplest question — how far can the structure reach without getting in the way?
