In the last twenty years, the thermal insulation and visual properties of glazing systems have improved considerably in the construction industry. Coated with ultra-thin silver and filled with inert gas, the standard insulating glazings used today have reached a high quality. Complex assembly, several centimetre- thick glazing and the use of expensive inert gases means that there is still potential for innovation in developing these glazing systems. Vacuum glass offers such a new alternative.

A Japanese and a Chinese company are already offering vacuum glass systems on the Asian market, however with Ug values between 1.1 and 1.3 W/m²K. The research project is looking to improve these values considerably. Using double-glazed assemblies with evacuated gaps, vacuum glass systems can achieve heat transfer coefficients of 0.8 W/m²K for the entire window and 0.5 W/m²K for the glazed area.

With system assemblies projected to be less than 10 mm thick with 4 mm glass, vacuum-insulated glass is thinner than conventional insulating glass units. It is no longer necessary to use inert gases. However, at ten tonnes per square metre, the atmospheric pressure on evacuated flat glazing is very high and requires the use of spacers in the cavity between the panes.

The goal of a research project funded by the Bundesministerium für Wirtschaft und Technologie, the German Federal Ministry of Economics and Technology (BMWi), is to investigate the technical feasibility of permanently vacuum-tight glazing systems that would be competitive on the European market. A collaboration of three research institutes and five medium-sized companies is involved in this.