Innovative, light and flexible membrane constructions have increasingly attracted the attention of architects in recent times. For example, they can be used to cover large areas, permitting increased use of daylight by using transparent or translucent materials while at the same time avoiding direct glare effects. The glass or textile fabrics used can create impressive optical effects, but do call for new concepts in order to optimise the energy requirements of buildings for heating and climate control.

Highly developed materials can play a role here: when equipped with so-called low-e coatings, they behave like mirrors with regard to thermal radiation. In summer, they reduce the heat influx into the building, thus reducing the cooling load, while in winter they reflect thermal radiation from inside the room or space and transmit only a small fraction of this heat to the outside. For a long time now, low-e coating has been standard on glazing and makes a significant contribution to the thermal quality of insulating glass. These ultra-thin metal layers are vaporised onto the inner sides of double or triple glazing, and are thus well protected. Textile materials often have to withstand mechanical loading and exposure to the weather, however. This means that a high degree of robustness is required. Durable coatings are now available, but they do not yet have the desired low-e properties.

As part of a research project supported by the German Federal Ministry of Economics and Technology (BMWi), TAG Composites & Carpets GmbH along with scientists from ZAE Bayern have developed coatings that can be attached to fabrics in a mechanically stable manner while preserving the texture of the fabrics. The construction element then has the desired low-e properties and can also have any colour effect desired.

A prototype large-scale unit is evidence that this process is ready for the actual marketplace. In accompanying studies, researchers have investigated the various possible applications in old and new buildings, and have tested the civil-engineering prerequisites and limitations in the case of building refurbishment too. On the whole, the results pointed to an encouraging market potential, dependent on the production costs that will eventually be achieved.