Clear Roofing Material Brightens Vikings Stadium

Things are looking up for Minnesota Vikings fans.

The team has moved into U.S. Bank Stadium, which is roofed with the largest expanse (at 248,000 square feet) of ETFE material in North and South America. The triple-layered, air-filled, ethylene-tetrafluoroethylene film — used most famously on the Beijing Water Cube — introduces diffused sunlight to the stadium interior while affording fans views of blue sky and white clouds above — quite an improvement over the former Hubert H. Humphrey Metrodome's opaque roof.

"We leveraged Virtual Design and Construction heavily during the planning phase, fabricating the panels based on measurements in the model, not in the field," says Brendan Moore, Minneapolis-based Mortenson Construction's senior project manager in charge of the enclosure and roof. "We were able to complete the installation in five months."

Weighing 95 percent less than glass, 75 individual ETFE panels cover 60 percent of the stadium, and the tens of millions of dollars saved in steel support tonnage and by eschewing a retractable-roof option allowed for investment in massive hinged doors that facilitate natural ventilation at the stadium's ground level. Moreover, the panels are fritted through one layer to reduce their greenhouse effect.

"A colleague of mine termed it 'clear is the new retractable,' " says John Hutchings, principal in charge at HKS, which will likewise cover the new Rams stadium in Los Angeles with ETFE. "The quality of light within the seating bowl is phenomenal."

This article originally appeared in the September 2016 issue of Athletic Business with the title "Design Details." Athletic Business is a free magazine for professionals in the athletic, fitness and recreation industry. Click here to subscribe.