Within the building, the debating chamber provides the outstanding spatial experience. The hall is situated on the first-floor level. The floor of the chamber is sunk by up to 1.40 meters below this level to provide the necessary incline for the rows of seating. A number of elements combine to make this space particularly impressive: its great breadth, its equally impressive height, the large areas of glazing that admit daylight from all sides, and the sense of weightlessness created at the heart of such a massive build- ing. Foster’s intention was that the plenary chamber should be at the heart to the rebuilt Reichstag and should be light, open and visually and publicly accessible. Twelve slender spun-concrete columns support the outer ring of the roof, form which an equal number of tapering beams cantilever out to bear the load of the inner ring. This in turn supports the mirrored cone. These columns are visually elegant, and slender in diameter, and they mediate visually between the circular shape of the chamber and the rectangular form of the building, which remains visible through the side windows to the two courtyards and the fully glazed walls of the eastern and western entrance halls.