The combination of curved glass and natural stone create a focal point on famous Königsallee Boulevard. The Kö-Bogen building (translated to “Kings Bow”) in Düsseldorf sits at the point where Königsallee Boulevard, a luxury retail district, converges with the scenic Hofgarten promenade. Designed by Daniel Libeskind, the unique structure combines modern curved glass and travertine stone to tie in both its natural and urban surroundings.

The complex design required an insulating glass (IG) solution that would satisfy the aesthetic and structural requirements of the building. Döring Glas from Berlin and Lindner Group in Arnstorf collaborated to run numerous tests to develop IG that would meet the demands of the curved and kinked glass elements of the design.

As part of the process, the team enlisted the technical assistance of Edgetech Europe GmbH, a division of Quanex Building Products.

According to Christoph Rubel, Edgetech’s European technical manager, “The glass elements were bonded both internally and externally, whereby the outer bonding acts like a mechanical safeguard. Glued glass connections required a UV-stable, silicone sealant. Using our Super Spacer® T-Spacer™ Premium Plus, the IG repeatedly passed compliance tests according to EN 1279 with standard IG silicones.”

The entire façade is 161,000 square feet, of which more than 23,000 square feet is curved and kinked glass with different radii and panel widths. This could only be achieved by a glass process with a flexible spacer that adjusts to any conceivable glass form and can be precisely posited down to the last millimeter on an automated line to ensure the parallelism of the glass pane.

The glass geometry of the Kö-Bogen building is unique in Europe and an architectural marvel that is complemented by the use of the flexible, high-performing Super Spacer T-Spacer Premium Plus.