U.S. Bank Stadium in Minneapolis, USA by HKS
This article was originally published on HKS Stories on Januray 21, 2018.
When U.S. Bank Stadium hosts its first Super Bowl, fans attending the game and the millions watching around the world will be struck by the stadium’s bold and modern shape, yet unaware of its underlying design strategies, technology integration and advanced building materials science. Pulling back the curtain, there’s a great deal of design drivers that informs the ‘why’ and ‘how’ behind the venue’s shape and unique materials.
HKS’ design was driven by four key components:
- Climatic Response: The authentic design responds to climate extremes rather than fighting them.
- Geography: Minnesota’s river and lake ice formations was a key design influence.
- Civic structures: The craft, character and materiality of Northern European design continues the region’s trend toward progressive and modern expression.
- Technology: Design driven by advanced material science and high-tech entertainment features keeps the stadium relevant.
Sustainable Roof System: Transparent Is The New Retractable
For just the sixth time in 52 years, the Super Bowl will be played in a cold weather city. In Minneapolis, game day weather could see a low of eight degrees Fahrenheit to a high of 25, the average local temperature on February 4. Whatever the weather decides to do, it’ll be perfectly comfortable inside U.S. Bank Stadium.
To manage energy use and costs while creating an atmosphere of an open-air stadium, HKS used a transparent and lightweight roofing material called Ethylene Tetrafluoroethylene (ETFE), which combines solar thermal heating and natural daylighting, reducing demand for artificial lighting and heating or cooling the structure.
Consisting of 60 percent of the roof surface, the transparent ETFE lets light in, but is lighter and more economical than glass. The ETFE is combined with nearly 200,000 square feet of glass windows, walls and doors throughout the building, providing a true indoor-outdoor experience to make visitors feel as if they are sitting outside without being exposed to the elements.
The ETFE roof panels contain a pattern of small dots, called “frit,” which helps to deflect the solar heat gain from entering the building which reduces heat in the summer months. U.S. Bank Stadium is the first building in the United States to use ETFE at this scale. By using ETFE, we reduced the roof structural steel demand by an impressive 2,000 tons.
The asymmetrical, angular roof is designed to shed snow, with a steeper roof plane on the north of the building than its counterpart to the south. The roof and its form creates a lofted interior “heat reservoir” that stores solar heat, which in turn acts as a natural snow melt system. The form of the building allows air to circulate and move through the stadium in both winter and summer months in a way that is fundamentally new to this building type, but closely connected to the way buildings were traditionally constructed as a response to similar climates.
The design has a measurable energy reduction impact: the stadium reduces energy usage by 16 percent by way of heat recovery, air handling units, ventilation and high-efficiency motors, and with the incorporation of LED sports lighting, the stadium reduces energy used for lighting by 26 percent.
ETFE systems have a carbon footprint about 80 times less than comparable glass systems. Combined with the system’s life expectancy and its capacity to be completely recycled, ETFE is one of the most sustainable building materials available.
Contextual Design Aesthetic
Minnesota is known for its lakes and rivers that freeze in the winter, creating jagged ice formations that change form as they expand and contract. The geometry of these ice formations was a key design influence for U.S. Bank Stadium. Northern European design also inspired the HKS design team. The authentic design responds to the climate like a true Nordic structure.
We were also inspired by the warm and welcoming character of the region’s residents, which informed our design thinking around the stadium arrival. We wanted to connect the stadium to its city in a literal and symbolic way that would complement the sleek, modern building façade.
This idea is manifest at the stadium’s Legacy Gate featuring the world’s five largest pivoting glass doors, which stand between 75-95 feet tall, each extending 55 feet across. The doors welcome fans in a larger-than-life way, and during good weather, open toward a new urban plaza and views to downtown Minneapolis.
High Tech, Up-Close Engagement
The Vikings consistent focus has been on creating an unforgettable experience for all fans. U.S. Bank Stadium boasts the closest seats to the field – just 41 feet –in the NFL amid a variety of seating options, including clubs and loges. Two of the NFL’s highest-quality and best-positioned LED video boards flank both end zones. The stadium has 2,000 televisions, an incredible art collection, an interactive Vikings Voyage fan space and 1,300 Wi-Fi access points.
The design discovery process is unique and different each time we design a new stadium. We get to dig deep into the psyche of a city, its culture and people so we can create a place that reflects their spirit and makes them proud. We get to explore the type of events the space will host, and what sports and entertainment will morph into 20 and 30 years from now, so the places we design are flexible enough to stay relevant. This creative process frees us up to see the possibilities of what the space can and will do, and doesn’t hold us to any standard or preconceived ideas.
Our groundbreaking design and the deep research process we apply to understanding the demographics, markets, socio-economic and operational factors is the way we approach every sports and entertainment venue we design, no matter the location, size, scale or sport, amateur or professional. We help owners and cities realize the future value of their venue by creating experiential environments that raise the quality of the entertainment experience and maximize loyalty.
Size: 38 acres (15,4 ha), 1.8 million sq ft (∼1 700 000 m²), 66,200 seats
Services: Architecture, Master Planning, Interior Design, Environmental Graphics, Branding
Project Features: 131 suites, 7,500 club seats, Party Plaza, Hall of Fame Museum, LEED Gold certification
Awards: World Architecture Festival – Winner (Completed Projects: Sport)
By Mark Williams, HKS Principal, Director of Sports & Entertainment Business