Aesthetics and energy efficiency of rounded façades

Reliable insulation of curved windows

The words ornate, functional and aesthetic could all be used to describe the new buildings in China’s cities. Nowadays, many architects’ plans are trying to bridge the gap between traditional and modern. In this context, rounded corners are often used to provide smooth transitions to solid building shapes. Overall the curved façade, which is made predominantly of glass, exudes a traditional harmony and makes buildings feel more inviting. So that the ecological aspect of the building doesn’t get neglected, ways must also be found of reliably insulating curved windows. Because insulating a rounded façade pays off. Thanks to what is an energy-efficient building design overall, the operating costs per square metre can be significantly reduced. The façade is then highly insulating and achieves an excellent thermal transmission coefficient.

Thermal separation of insulated glazing

Suitable for this are Warm Edge spacers, which are used for the effective prevention of thermal bridges in windows. Thanks to their thermal separation they reduce heat losses at the glass edge of the insulating glass. They thereby save on heating energy requirements, increase comfort in the room and reduce the risk of condensation being formed on the glass edge. Warm Edge spacers such as Thermix® from the German company Ensinger can be precisely adapted to the building’s architectural concept. These Warm Edge spacers, made from highly insulating plastic and with an integrated metallic diffusion barrier of high-quality, stainless steel, are available in several sizes and colours. They can also be easily bent so as to follow the window’s stylistic elements.

How to equip curved insulating glass with rigid Warm Edge spacers

To achieve rounded façade elements, each pane is bent to the required radius using a special hot-bending process. The inherently rigid Thermix® Warm Edge spacers from Ensinger can be bent in such a way that they also optimally insulate the curved insulating glass. Special manual roll formers adapt the plastic profiles via their edge to the required radius, precisely and without any folds. As a result the spacers with their integrated stabilising wires reliably retain their shape.

The pre-bent profiles are subsequently filled with adsorbent as normal, fitted with butyl tape and then assembled to produce frames using corner keys. The triple insulated glass is subsequently built up from inside to out. The elements are pressed together using cramps, noble gas is introduced and the glass sealed. The customer-specific pane shape is now ready for installation. In this way, individual requirements can be fulfilled thanks to high-quality materials.


When panes of insulating glass have to be bent to achieve the desired style of a building, aesthetic and energy-efficient construction is easy with the right spacer. Warm Edge spacers such as Thermix® from Ensinger are robust thanks to their integrated stabilising wires and are easy to handle and process further. The profiles can be bent cold in any axial direction. This allows spacer frames to be simply produced for straight as well as curved pane profiles; this ensures excellent thermal insulation values as well as outstanding productivity and quality for insulating glass manufacturers.

For more information, go to:

Ensinger is exhibiting:

23. – 26. October 2018
Düsseldorf, Germany

13.-16. November 2018
Madrid, Spain

14.-19. January 2018
Munich, Germany

Photo 1 and 2: Curved insulating glass elements are an eye-catching architectural feature, with Thermix spacers creating a “Warm Edge”. The required bending radius is produced simply and precisely without any folds using a manual roll former.

Photo 3 and 4: The pre-bent spacer is filled with desiccant, fitted manually with butyl tape and then assembled to produce frames using corner keys.

Photo 5 and 6: Using the spacer frames, the triple insulating glass is built up in layers from inside to out, pressed together and the gaps between the panes filled with argon.

Photo 7 and 8: The gas valve is closed and the insulated glass assembly is sealed using a secondary sealant.

Photo 9 and 10: The curved façade elements made of triple insulating glass are lifted with the aid of a crane and placed in position from the raised platform.

Photo 11, 12 and 13: The precisely fitted insulating glass elements are then permanently connected to the supporting sub-construction using aluminium trims.