159 Poster 12 Glass Architecture, Beyond Mere Transparency P.M.J. van Swieten*, K. Lagendijk*, F.A.Veer *, *Faculty of architecture, Delft University of Technology Keywords 1 = Architecture 2 = Transparency 3 = Design Abstract One of the limitations of glass in architecture is that in its ultimate application, a complete glass building, the entire concept of architecture is denied by avoiding form, shape and contrast. Thus the still increasing usage of glass in conventional architecture will soon be ended by its lack of architectural expression. The shear success of the use of transparency limits the further development of glass in architecture. To develop glass further a completely different approach is needed. The weakness of the conventional approach to glass is that it only looks at the use of transparency. In reality glass offers more. Although glass can be transparent the use of coloured, tinted and translucent glass offers possibilities for architectural expression that extend the possibilities of glass. In addition the transparency and reflectivity of glass it is possible to use different methods of illumination to create a non constant architecture that can adapt and gives different expressions at different times. Introduction The history of glass in architecture goes back over a millennium. Over this period it has evolved from the glass rose windows of medieval European cathedrals, through the great glasshouses of the 17 th and 18 the centuries to Crystal Palace in the 19th century. This resulted in the early 20 th century attempts at open buildings exemplified in the Netherlands by the glass palace in Heerlen, designed by Peutz in 1938, illustrated in figure 1. The architectural detail shown in figure 2 exemplifies the philosophy, the glass, which composes most of the façade surface, is not even shown. Structural possibilities Research in the last couple of years has shown that glass can be used in a structural fashion going beyond anything considered possible 20 years ago, [1,2,3]. Starting from the assumption that buildings that are completely transparent above the ground level are possible; several students in the materials and structures laboratory of the Faculty of Architecture of Delft University of Technology have made designs for buildings, which only use transparent building components. After studying the effects of foundation shifts [4], wind and snow loading [5] and designing a family of components for such a building [6] the basic conclusion is that such a building is possible. Figure 3 shows a concept for such a building. Using advanced glass- polycarbonate laminates, laminated glass using PVB and some transparent polymer components the structure schematised in the upper part of figure 3 can be realised. This building has transparent floors, stairs, etc. If this structure is visualised using modern computer techniques a visualisation of the structure can be made. This is shown in the lower part of figure 3. This also shows the limits of a pure engineering approach. The building, although structurally sound, is devoid of any architectural expression. Fig 1 The glass palace in Heerlen designed by F. Peutz in 1938 Fig 2 Architectural detail of the windows of the glass palace (provided by ABBC-bouwadvies) Fig 3 Transparent building study, top picture shows the structure, bottom picture is a visualisation of how it would look.