Stadium Letzigrund

The new Letzigrund: “The wonder of Zurich”

“The new Letzigrund has brought people together who want to create something unique for Zurich.” These words by City Councilor Kathrin Martelli on breaking the ground at the start of an unusual project were as valid during the building work as they are today. “The start was successful and our teams are motivated. We want to ensure that both fantastic world-class meetings can take place here as well as Euro 08 in Zurich. This is no simple task, but I know that our team will manage it. In this sense the new Letzigrund construction, after the St. Jakob Park in Basel and the La Praille stadium in Geneva, are further proof of our competence in stadium construction,” said Hans-Peter Domanig, CEO of Implenia Real Estate at the ceremony.

From excavation to the concrete
Immediately after cutting ground on November 15, 2005, Implenia began with excavations. A total of 300,000m3 of earth was moved – with part of it turned into concrete on the construction site itself. The earth was sieved into its various components and remixed according to requirements. For this task, Implenia installed a mobile gravel plant.
The 30,000m3 of concrete was largely produced from the local ‘limmat’ gravel, a factor which drastically reduced truck journeys and attendant emissions.

The carcass in stages
Work on the building shell actually began during the FIFA World Cup. Because of the tight schedule, the challenge was to lose no time but to begin immediately with building work while ensuring that games and, in particular, the athletics meeting in 2006 could still be hosted by the Letzigrund stadium.
Immediately after the FCZ’s last match am May 6, 2006, building work in the south of the old stadium was started. Until the August 18, 2006, the date of the world class meeting, the old stadium had to remain in operation. To this end, a retaining wall was created so that the work on the shell of the main grandstand to the west could go ahead.

The stands
The winter of 2006/2007 was a critical phase because the stands on the north, east and south sides had to be built during the winter months. The mild weather proved a boon to the builders so that this work too could be completed on schedule.

The pitch
Already two months before the demolition, before the fans filled up the old Letzigrund pitch with their pizza trays, a new pitch was sown at a specialized farm near Ingolstadt, Germany. Two varieties of grass were sown at different times – one which germinates quickly and another that grows at a slower rate. To give the slower growing variety priority, the fast kind was sown at a later date.
After that, the pitch was mowed three times a week, with the cuttings being vacuumed rather than cleared with rakes. Because the pitch has to get used to being walked and run on, it was constantly maltreated with a specially made cleat roller.
On August 6, 2007, the pitch was delivered and unrolled in the presence of the media.

Dancing supports and a flying roof
The famous “dancing supports” were put into position at the beginning of June 2006. Each of the 31 supporting pairs had to be placed to a precision down to the millimeter under the supervision of a geometer. Any mistake, and it could never be rectified. In this way the impression of a flying roof was created.
In fact, the new Letzigrund stadium project has already won an award for the steel construction: the Prix d’Acier presented by the SZS. The new Letzigrund stadium qualified as a steel-girder construction for the competition in 2007.

Track magic
The Letzigrund’s track was world famous, so much so that many athletes adapted their style to the Zurich meetings to attempt record-breaking runs. The new track is designed to be just as magical. The Conipur-M surface selected is made of solid material in three layers, colored throughout and with a thickness of 14 mm. The product is Swiss-made and certified by the international athletic association.
At the end of July/beginning of August the liquid granulate was poured in, hardened over night and swept away the following morning. The process was then repeated. Because no rain can fall during this process, only sunny weekends were chosen.

Functionality and safety
In safety terms, the new stadium is impressive thanks to its use of the very latest technologies, acoustics to match and an ingenious safety concept with stadium and video surveillance.
Functionality was high on the list too and the stadium’s inner workings are unique. A track in the interior lets athletes run a full 100-meter circuit. There is also a gym for them to warm up and train when the weather’s bad. The player cabins are decorated in a variety of stimulating colors with lockers finished in wood, and have parquet or charcoal gray floors.
Many people were skeptical about the color of the chairs right to the end. Shouldn’t Zurich have a blue track and blue chairs? However, the chairs in combination with the red track produces a balanced harmony that is continued in the color of the roof underside.

Ecology

Implenia has succeeded in setting new ecological standards with the Letzigrund building project.
Among the innovations were: use of excavated material on site reducing truck trips and careful reconversion with 94% of the old stadium being reused.
Plus, all trucks used comply with the Euro 3 emission standard and had their wheels washed onsite to prevent dirty streets around the stadium.
Permanent measuring points meanwhile ensure the quality of air, checking for dust and groundwater quality and vibrations.
The roof vegetation ensures stability, forming an ecological island for bees and birds, and also effecting the climate in the stadium itself.
Photovoltaic elements are used to collect energy.