The Minnesota Sports Facilities Authority has put a draft 389-page Environmental Impact Statement for a new Vikings stadium up on its website, and it's got some intriguing new details about what's to come.
To paraphrase the oft-quoted scene from The Graduate:
We just want to say one word to you. Just one word. Are you listening? ETFE.
Technically, the name is ethylene tetrafluoroethylene. It's an architectural polymer that's mentioned in the EIS, and made famous as the translucent exterior of the Beijing National Aquatics Center, among other places. There's a whole bunch of pictures of other architectural uses over at the website of Vector Foiltec, which makes the Texlon version of the material.
Three landmark buildings that use ETFE
Here's what the draft EIS actually has to say about the material and its use in the new Vikings stadium. The document leaves open some of the most intriguing questions, like whether there will be an open wall or a retractable roof on the new stadium. But there are other details:
"Draft design plans reveal that the new stadium would be a bold, iconic, geometric structure with long, sloping, angular facets that are primarily directed toward the downtown Minneapolis skyline. Each of the building facades is a dynamic blend of metal panels, and transparent or translucent curtain wall, or ETFE (ethlylene tetraflouroethylene) membranes.
The draft design plans show the new Stadium facades are a combination of metal panels, aluminum curtain wall systems and Kasota limestone. The west elevation, also the proposed main entrance, features a video board behind perforated metal panels. Both the east and west elevations include three options for large sections of aluminum curtain wall: fixed, pivoting panels and sliding panels.
The draft fixed roof design option uses stainless steel metal panels and integrates snow management gutters and a sub roof with a snow management basin. On the more vertically oriented faces of the roof, a clear or fritted ETFE membrane system is proposed and would allow natural light into the stadium. The draft operable-roof design option uses the same materials as the fixed roof option, but has one large or two smaller panels that create an opening in the roof."
"Fritted," by the way, apparently means patterned or printed in some way, when it comes to architectural membranes.
ETFE shows up in another recent stadium design. On the same day in September that HKS Architects was chosen to design the Minneapolis stadium, officials in Tampa Bay were unveiling a design of a proposed Rays stadium by HKS -- and featuring the possible use of ETFE for the roof and back wall.