A team effort involving planQuadrat (Karlsruhe), Züblin (Stuttgart) and ECE (Hamburg) refined the design of the double-leaf glass façade conceived by Benthem Crowel. The outer leaf to the façade incorporates horizontal rectangular hollow section rails suspended from tie bars fixed to steel brackets at parapet level. The horizontal rails are the framing members for the large rectangular panes of glass. An innovative proposal by seele enabled the suspension construction to be optimised, thus allowing the pane formats to be enlarged and the aesthetics of the façade improved. The panes of laminated safety glass were manufactured by seele at its own plant using the so-called SG laminating process. This new process enables the permissible loads on the panes to be increased. In addition, the panes are thinner and can therefore span up to 5m.
And the consequence of that is an external envelope formed by just a few large-format panes, leading to a serene segmentation of the elevation and lending the façade the appearance of a flat sheet, emphasized by the pattern of dots printed on the outer panes. Furthermore, finetuning during the planning process reduced the number of supports for the open-grid flooring between the leaves compared with the number originally proposed in the tender.