Forsyth Barr Stadium

Forsyth Barr Stadium in Dunedin, New Zealand, is the most southerly professional stadium in the world. With Dunedin’s cold, wet, blustery climate and an existing facility falling increasingly below acceptable standards, the NZ Rugby Union decided the city needed a new stadium. Forsyth Barr Stadium was completed in time for the 2011 Rugby World Cup.

CHALLENGE. An all-weather venue was the obvious choice for the stadium, but given the modest size of the city (119,000 people), it was difficult to justify the cost of an enclosed venue for sporting matches only. It was eventually agreed that if the stadium was enclosed it should be used for a variety of purposes, including sporting, cultural, entertainment and educational uses.

The design team was then faced with the challenge of creating a cost-effective stadium with a natural grass pitch growing under a fully fixed roof. Populous’ broad experience with covered venues around the world brought valuable insights and for two years the design and research team studied different materials for roofing the stadium and their effect on optimal grass growth. The final solution was ETFE (ethylene tetrafluoroethylene) – a transparent polymer originally developed for the space industry. The research also clarified that the stadium design would be driven primarily by the requirement to maximize sun strike levels and natural ventilation. The ETFE covers the roof and part of the facades and the stands on the Northern end are lower to allow maximum sunlight onto the pitch. The end facades are raised 5m above ground to allow fresh air across the pitch.

INNOVATION. Forsyth Barr Stadium is the world’s only permanently covered stadium to boast a natural turf playing field. Whilst ETFE is not a new product, this is the first time its UV translucent properties have been put to use in a stadium, creating the largest ETFE covered structure in the Southern Hemisphere. Dunedin’s cold and wet climate makes the roof an essential feature of the stadium to encourage crowds to attend live events.

The stadium is also New Zealand’s largest rectangular indoor event venue. It has 20,000 permanent seats, 11,000 temporary seats and a 37-metre internal roof height, which combined with the angled seating pitch, means spectators are incredibly close to the action. Construction was completed within both a tight timeframe and budget.

IMPACT. During the research and early design stages, an ETFE test rig was built on site to monitor grass growth both under the rig and outside it. Toward the end of the testing phase, it was discovered that the grass under the rig was stronger and healthier than the grass surrounding it, withstanding several high impact tests by local rugby.

The success of the grass growth due to the innovative testing process and use of ETFE has set a new benchmark for North American and Northern European venues for the feasibility of grass growth under an enclosed structure.

In September 2011, the stadium played host to a number of pool matches during the NZ Rugby World Cup and received great critical acclaim for the condition of the pitch and the levels of spectator comfort within an enclosed venue. In November 2011, Elton John was the first entertainer to perform at Forsyth Barr Stadium which has now staged international and domestic rugby matches, major music concerts, movie screenings, and Red Bull snowboarding competitions.