The central structure reveals itself to full effect at dawn and dusk: a free-standing ellipsoid form with a total of 13 storeys of different size. The elliptical floor plans, with radii up to 25 m, are supported by radial steel beams flexibly fixed to multiply curved vertical girders.

The outer skin overlooking the atrium consists of large printed panes of glass. This glazed »lantern« is enclosed within a 4,000 qm facade – a patchwork of 3,000 oak windows from energy renewal schemes all over the EU – braced by a rhombus-shaped structure of steel beams.