ETFE(ethylene tetrafluoroethylene) has emerged over the previous 20 years as one of the most transformative materials in stadium architecture. It was initially established by Depont for aerospace applications. Its inherent residential or commercial properties– light transmission, structural effectiveness, resilience, and minimal weight– have actually made it especially fit for long-span architectural applications.
ETFE was initially introduced in architectural applications in the mid-1980’s but got more traction in the late 1990’s and early 2000’s as designers sought options to glass and material for large scale structures.
Eden Project was an early proof of idea that revealed the material’s structural efficiency and sturdiness.(Jürgen Matern/Wikimedia Commons/CC-BY-SA)
The Eden Task (2001) by Nicholas Grimshaw in the U.K. was an early evidence of idea. It utilized ETFE cushions to produce a series of transparent domes that emerge like bubbles amid a verdant landscape. While in 2005, the Allianz Arena in Germany by Herzog and de Meuron developed ETFE as a defining material in stadium design. Its inflated ETFE facade panels, capable of changing color, showed how the material might work not only as a structure envelope however as a dynamic architectural declaration.
At Allianz Arena the inflated ETFE facade panels can changing color. (Richard Bartz/Wikimedia Commons/CC BY-SA 2.5)
Over the next 10 years across Europe and Asia, ETFE ended up being progressively common for diverse building typologies needing light-weight structures, natural daytime, visual transparency, thermal performance and visual expression. It began to establish itself as a viable option to glass and fabric in most structure typologies and a favored material for stadiums. The Beijing National Aquatic Center (“Water Cube”) utilized ETFE to create a meaningful facade and roofing system at the 2008 Summertime Olympics. In 2011, the Forsyth Barr Stadium in New Zealand ETFE delivered the first totally confined stadium with a natural turf pitch.
In contrast, The United States and Canada was slower to adopt ETFE, partly due to the requirement for brand-new screening procedures to meet U.S. building codes and the industry’s risk-averse culture, which enhanced an enduring dependence on standard products. With relation to stadium applications, throughout this duration North American stadiums either highlighted outdoor venues or integrated retractable roofs where conventional nontransparent products were suitable. From 2008 to 2016, I was vice president of exterior engineering at Thornton Tomasetti, leading ETFE style efforts on major stadiums including U.S. Bank Stadium, Acid Rock Arena, and the BMO Arena.
U.S. Bank Arena in Minneapolis ended up being the very first NFL arena to utilize ETFE at scale. The arena combines ETFE with a retractable roofing
.(Myotus/Wikimedia Commons/CC0 1.0 )The U.S. Bank Arena in Minneapolis ended up being the very first NFL arena to use the material at scale. Completed in 2016, the project includes 240,000 square feet of ETFE. Preliminary ideas required the combination of an operable roof, the popular technique of the day. Nevertheless, with the desire to pivot toward a more ingenious solution, we pressed the principle of incorporating ETFE by offering the concept as the “new retractable.” Here, ETFE offered the best of both worlds: the visual connection to the environment, comparable to the open ode of a retractable system, while supplying spectator and gamer comfort more connected with the closed mode all within a more cost-effective repaired roofing structure. This project demonstrated ETFE’s advantages and effectively verified the product for large-scale NFL applications.
During that very same period, I dealt with the restoration of Hard Rock Stadium in Miami. Here we integrated ETFE at the inner edge of a new light-weight canopy and developed complex “oculus” skylights around massive masks that supported the whole canopy. This was a brand-new method in the U.S., an outdoor stadium that incorporated localized defense for viewer convenience, a shift toward passive environmental strategies instead of completely conditioned domes. In addition, the task quietly placed itself as the most sustainable arena in the NFL by recycling a significant part of the old arena, lowering brand-new products and cutting overall embodied energy by nearly 70 percent.
At Hard Rock Stadium in Miami, designers integrated ETFE at the inner edge of a new light-weight canopy and developed complex “oculus” skylights around enormous masks that supported the whole canopy. (Elbert Hampton/Wikimedia Commons/CC0 1.0)
BMO Arena represents an important action in the development of modern stadium style in the United States, translating lessons from Hard Rock Arena into a more refined, climate-responsive canopy. The development continued with SoFi Stadium in Los Angeles, finished in 2020. The arena took the partial al fresco typology to a brand-new scale, by developing a canopy that covers over the entire stadium and the surrounding plaza and amuse district. The canopy, a cable-net with a single layer ETFE application became the arena’s specifying feature. SoFi’s application leveraged ETFE’s light-weight residential or commercial properties and structural capabilities making the ambitious scale viable.
Sustainability is a critical consideration. An ETFE roofing system delivers a lower life-cycle carbon footprint than conventional enclosures. While carbon-intensive per pound, its ultra-lightweight properties considerably decrease overall product use, decreasing embodied carbon while also minimizing structural steel need. When evaluated holistically, ETFE offers a considerably more sustainable option for large-span arena enclosures.
Together these tasks mark a shift in stadium design in The United States and Canada and ETFE is poised to play a critical role in the next generation of NFL stadiums.
Today, I lead my own practice concentrated on the combination of architecture and engineering to deliver innovative, high-performance style services. This approach is shown in our proposal to reimagine Soldier Field for the Chicago Bears, where we used lessons from numerous years of arena style, urban planning, and advancement to address both technical and civic obstacles.