The Eden Project Biomes
Prior to establishing Exploration, Michael Pawlyn was central to the Grimshaw team that set out to radically rethink horticultural architecture.
Inspiration came from a range of biological structures including soap bubbles, carbon molecules and radiolaria. The result is one of the lightest structures ever created and a building that is largely self-heating using passive solar design principles.
While working on the Eden Project we turned to nature at every stage in the design process – looking at clusters of bubbles for the form, to the structure of a dragon fly wing to resolve the way steel members intersected at the junctions.
The idea produced by the Grimshaw team was for a string of bubbles. The diameter of the bubbles could be varied to provide the growing heights required in the different parts of the building and the necklace line that could be arranged to suit the approximate topography of the site, minimising the amount of ground shaping required and allowed the solar orientation of the building to be optimised.
The visionary architect Buckminster Fuller had demonstrated that the most efficient structure for a spherical surface is a geodesic arrangement of hexagons and pentagons. By cutting away the parts of the bubble model that would be below ground and applying a geodesic structure to the surface we arrived at the first image that looked something like a building. Many different iterations of this design exercise were carried out in order to optimize the building form and it’s position on the site.
The design of the enclosing membrane led the team towards ETFE – a high performance polymer that is assembled in triple layer ‘pillows’ that are then inflated for structural rigidity. ETFE offered multiple benefits resulting in a virtuous circle of efficiency: the ETFE pillows could be made much larger than glass and were 1% of the weight (a factor 100 saving in embodied energy). This substantially reduced the amount of steel required and allowed more sunlight into the building.
The end result was a radical reinterpretation of the greenhouse - an extremely lightweight enclosure that is self-heating for most of the year. The weight of the superstructure for the Humid Tropics Biome is less than the weight of the air that it contains. Having worked through the design process it is now possible to make a structure that is even lighter.
The scheme has won numerous awards and, during its first three years of opening, contributed £0.5 billion to the local economy - a truly transformative idea that inspires on so many levels.
Client - Eden Project Limited
Architect - Grimshaw
Environmental Engineer - Arup
Landscape Architect - Land Use Consultants
Structural Engineer - SKM Anthony Hun