(continued)

The Construction

Initially the sides of the pit were very unstable. They were shaved back to a safe angle and terraces chopped out. Two thousand rock anchors, some up to 40 feet (12 meters) long, were driven into the sides to hold them back.

The foundations of the biomes run along the bottom and up the back wall of the pit, 6.5 feet (2 meters) wide, 5 feet (1.5 meters) thick, and 2800 feet (858 meters) long.

Alan Jones, project director for Anthony Hunt Associates said, "For the foundation beam to perform competently it had to be treated as a continuous entity."

The biomes were erected with a combination of cranes (static and mobile) and scaffolding. The scaffolding made the Guinness Book of Records. At 192 feet (58.5 meters), it was the highest freestanding structure in the world.

The scaffolding also broke the record for the largest volume in one structure, at 6.9 million cubic feet (195,600 cubic meters). The components, if laid end to end, would stretch 230 miles (370 kilometers) in length!

The ETFE cushions, made and fitted by the German company Foiltec, were installed by the "sky-monkeys" — construction workers using mountain-climbing techniques.

The Biome Link

The two biomes are joined by "The Link," a grass-roofed building that blends into the surrounding landscape, giving the impression that the biomes rise out of the ground.

It is basically two structures in one, providing a corridor linking the biomes as well as an exhibition, refreshment, and toilet facilities area.

The Link is sunk into the landscape, with the dining areas fronted by a sweeping glazed wall shaded by cedar louver screens.

The Visitor Center

Facing The Link and the biomes, from high on the opposite side of the pit, is the visitor center, which is the entrance to the complex. It merges into the lip of the pit and falls in line with its contours. The front is clad with split cedar wood shingles, and the rear is a long curving terracotta wall of rammed earth. In between is a mall-like courtyard partially covered by a tented fabric roof.

The curvaceous building, which is steel-framed, provides the visitor with a refreshments area along with the inevitable souvenir and plant retail outlets. The roof, which is a structural metal deck with insulation and a capping sheet over, forms part of a shallow cone.

Both the link and visitor center were modeled on Robot Millennium structural analysis software.

The Landscape

The design team was asked to create a level planting area in the center of the pit and to provide access to visitors without losing the drama of the site.

The sculpted landform includes intimate spaces, such as "Wild Cornwall" with its unusual themed sculptures, interspersed with the memory of its quarrying past. The curving paths and ramps conjure up images of a Tuscany landscape.

The architectural structures only account for about a quarter of the landscape. The rest is made up of themed zones of more temperate plants and sculptures planned by Land Use Consultants.

Other major works at the site carried out by the McAlpine Joint Venture have included a new 2.25-mile (3.6-kilometer) access road and cycle path flanked by Cornish boulder hedges.

The road construction, on a greenfield site, has created 15 acres (6 hectares) of new wetland habitat. Paved parking areas for 2,000 cars have been provided on terraces, along with hard-wearing grass areas for overflow parking.

Respecting the Environment

The water extracted from rain and spring sources is collected and stored in a large underground tank before being pumped into the water distribution system via a filtration and disinfection plant. The water is used for toilet flushing and irrigation of the plants.

The project's total projected annual water requirement is approximately 16 million gallons (62 million liters). Of that only 20 percent is expected to come from the standard water supply.

The architecture and landscape create an unparalleled experience. Attendance figures far exceed expectations, and there are more buildings planned. These include a third, arid, biome, a stand-alone education center, and a 200-bedroom hotel.

The major criticism — one visit is just not enough! Because of the dynamic nature of the site, follow up visits are a necessity. Where are those train tickets?

Don Barker is a freelance writer and photographer in London, UK, who has lived and worked in Europe, Australia, Thailand, Sri Lanka, Hong Kong, and Singapore.

Client: Eden Project Ltd.
Architects: Nicholas Grimshaw and Partners
Landscape Architects: Land Use Consultants
Civil and Structural Engineer: Anthony Hunt Associates
Steelwork Contractors: Mero UK (biomes); Snashalls (visitor center); Pring & St. Hill (biome link)
Quantity Surveyor: Davis Langdon & Everest
Geotechnical Engineers: John Grimes Partnerships
Design and Build contractors: McAlpine Joint Venture
Services Engineer: Arup
Project Manager: Davis Langdon Management
Project Supervisor: Land Architects
Planning Supervisor: Aspen Burrow Crocker
Fire Consultant: Arup Fire
Cladding Consultant: Arup
Access Consultant: Purcell Miller Tritton
M+E Subcontractor: Colston

Comparison between humid tropics biome and the Palm House at Kew Gardens in West London. Image: Nicholas Grimshaw and Partners The curving paths and ramps conjure up images of a Tuscany landscape as they rise towards the visitors center. Photo: Don Barker The visitors center. Photo: Don Barker A cool-air vent at the bottom of the warm temperate biome. Photo: Don Barker Steel arches at the intersection of two domes, showing the separate diagonals connecting the node points of the layers. Photo: Don Barker The massive air-flow units controlled by software. Photo: Don Barker A cast steel node where the hexagons connect. The steel pin is used as a secure fixing for access scaffolding for maintenance workers. To the right is one of the giant vents that draws in cooler air. Photo: Don Barker The geodesic structure of the humid tropics biome. Photo: Don Barker   Click on thumbnail images to view full-size pictures.