Façades with curved glass elements are on the rise. One of the most eye-catching projects of the decade from 2000 to 2009, and also one of the first of its kind in Europe, was the Hotel Wagram in Paris. The wave-shaped façade was designed by the Christian de Portzamparc studio, and was constructed in 2009 by the façades specialist Seele. At eye level for the passers-by, straight glass rows, made of windows that are 2 x 4.3 metres thick, run along the ground floor that are designed with the Super Spacer® TriSealTM Premium Plus in the area of the edge seal and with a silicone seal on the vertical pane joints. For panes of this size it was important that the profile design is capable of absorbing the movements of the upper floors. In addition, the edge seal with the flexible spacer in the insulating glass had to absorb the thermal and dynamic loads of the glass panes that had become stiff through the bending process, and moreover, together with the silicone sealant, ensure the longevity of such valuable façade elements. Curved double-glazed insulated windows form the characteristic waves in front of the hotel rooms on the upper floors. The elements are 2.60 meters high and up to 4.30 meters wide and are manufactured with 11 different radii, ranging from 900 to 1,100 millimetres. Christoph Rubel on the special challenges for the all parties involved in the project: "Due to the bending of the glass, the surface tension is no longer evenly distributed across the individual panes, at the same time the stiffness is higher than in the case of flat glass. If mechanical loads, such as climate stresses or winds, act on the curved panes from the outside, they thus stress the edge seal to a much greater degree than plane glass. The glass type and thickness, the age and weather-resistant secondary sealants and façade adhesives as well as an elastic spacer interact together to ensure the longevity of the entire construction.