Revitalisation strategies for modern glass facades of the 20^th century

Modern glass facades of the early and mid 20^th century have always been synonymous with innovative and sophisticated building concepts. These building skins were often established as a feature reflecting international stylistic standards, enhancing the prestige of builders and occupants - although often independent from or even in contradiction with climatic requirements and local conditions. In particular, in Central Europe varying strategies for the revitalisation of modern glass walls, facades and windows have been developed and realised. Multi-storey and high-rise buildings from the 1950s and 1960s, such as Haus Hardenberg by Paul Schwebes (1955-56) and Europa-Centre by Helmut Hentrich and Huber Petschnigg (1965), both in Berlin, are typical facade constructions. The very diverse approaches of revitalisation of Haus Hardenberg and the Europa-Centre will serve as examples to be compared and described with regard to different planning and decision frameworks. Both buildings have passed through certain episodes of modification and revitalisation. Both are preserving their original appearance, but while the original facade construction of Haus Hardenberg has been maintained and modified, the single glass facade of the Europa-Centre has been totally changed into a double facade system. The architectural design, construction, functions and environmental qualities will be described and evaluated with regard to the original concepts and requirements. These buildings will be presented addressing their impact on the refurbishment of modern building skins in general and in relation to increasing energetic requirements. In this context newly developed steel profiles have been investigated to be used as an alternative for the revitalisation of protected facade constructions. The way in which Modern Movement buildings in other countries and continents can be adapted to climatic and socio-economic conditions will also be discussed.