Computer rendering of redesigned lobby façades for Frankfurt’s Messeturm. ©Jahn – Matteo Thun & Partners

Completed in 1991, the Messeturm in Frankfurt is the second-tallest building in Germany, and recently seele helped it earn another milestone. The lobby at ground floor level was revamped by architect Helmut Jahn working with Matteo Thun & Partners to include both aesthetic and energy efficiency upgrades. Engineers from the Werner Sobek practice cooperated in the façade design, which features 17-meter high insulating glass units. Unique to this project, the panes of insulating glass bend to a radius of 24-meters. The use of flat panes arranged in polygonal form was ruled out, which meant that every pane had to be bent with a certain curvature.

Section through stainless steel post with glazing bar. ©seele

Seele says its team of designers, engineers, logistics specialists and erection crews developed the steel-and-glass elements in just seven months prior to work commencing on site.

“All our experience with oversize panes gained over the past 15 years was called upon for the Messeturm project. The result is a complete package involving the design, logistics and erection for these 17-meter high panes in the heart of the city, all from one supplier,” said Doris Erdt, senior design manager at seele GmbH.

One special feature of this façade’s design is that consists of only a few parts: nine lites and ten posts on each side of the tower. There are no horizontal members interrupting the glass, helping create lightness and transparency despite the dimensions. Due to the huge size, each lite required special bearings and had to be held in place with glazing bars. The cold-bent insulating glass units measure approximately 17- by 2.8-meters, are approximately 71-mm thick overall and are supported by stainless steel posts weighing approximately 3.5-tons each. The insulating glass has a solar-control coating on level 4 to reduce solar heat gains, combining aesthetic and functional criteria.

The first insulating glass units were set up in late July. ©Jessica Schäfer

The tight schedule, city-center location and cramped site conditions called for carefully coordinated logistics. Specially adapted inloader frames were used to transport the 17-meter high lites safely. Great care was also needed when operating the special glass lifting apparatus, which had about 90 suction cups for lifting the approximately 6-ton lites off the trucks and into position.

Each façade segment consists of nine cold-bent insulating glass units measuring 17 x 2.8m. ©Jessica Schäfer

“Everything had to work well together in this erection concept – people, equipment and nature. We plan every detail very precisely in advance and take account of all aspects that affect erection: wind, temperature and humidity are all crucial aspects during construction work,” said Dirk Herrmann, head of erection at seele.

The first façade segment with its nine cold-bent insulating glass units was completed at the end of August. ©seele
Special glass lifting apparatus with about 90 suction cups. ©Jessica Schäfer