The Foundation Building forms the third phase of The Eden Project, and was designed to accommodate the increased staffing levels of Eden Project employees. It offers a comfortable working environment for the administrative team as well as library facilities.

It is the practice's first building built to have an entirely PVC-free specification and uses its own environmental management system. The concept is to provide a highly insulated, lightweight timber box wrapped inside a breathable metal skin, with both skin and box punctured by a vertical light shaft.

Laid out over two floors, it follows a 6 x 14 m primary grid. Each floor is arranged around a central staircase and is largely open plan. There are timber-decked external terraces at ground and first-floor level and a projecting curved balcony extends beyond the building envelope.

The structure comprises a series of ten propped softwood glulam beams. Instead of the traditional flat floor slab, the building is raised off the ground, supported on slender, timber columns bolted to concrete pads.