Grimshaw developed the geometry of the copper-clad roof in collaboration with a sculptor, Peter Randall-Page, and Mike Purvis of structural engineers SKM Anthony Hunts. It is derived from phyllotaxis, which is the mathematical basis for nearly all plant growth; the "opposing spirals" found in many plants such as the seeds in a sunflower's head, pine cones and pineapples. The copper was obtained from traceable sources, and the Eden Project is working with Rio Tinto Group to explore the possibility of encouraging further traceable supply routes for metals, which would enable users to avoid metals mined unethically. The services and acoustic, mechanical, and electrical engineering design was carried out by Buro Happold.