The research of lighter and lighter products of the technology is today a constant within a lot of the frameworks of the applied sciences and in particular in architecture. Besides having a significant generally considered positive, effectively expressed by Italo Calvino in the first of his “Lezioni americane”, the lightness, if referred to a manufactured building article, involves also effect capable to make its assembling easier: more handling, economy in transport and in the assembling, higher safe towards accidents. It also underlines by its nature the technological innovation that is frequently assumed as category characterizing the new architecture. On the other side its use is however in contrast with other parameters that have to be considered in the application of the building components, first with the needs of thermical inertia, of sound-proofing and of durability. But there is another need, more relevant to the emotional sphere: the sensation of safe that, in the mark of a building tradition which has been expressing for centuries the architectural works using heavy materials as stone and bricks, is got from the perception of the structural masses, from the sense of stability and of perception that they arouse. Not measurable in any way, that esigence is and was often noticed also in a lot of examples of contemporary architecture, living together with the use of materials and components of high lightness. You con quote, as significant examples the faculty of History in Cambridge by J.Stirling, the residential area Thames Reach Housing in London by R.Rogers, the Bank of Lodi by R.Piano, but certainly are very numerous the works in which the effect of lightness produced thanks to the use of components realized with the glass, the aluminium, the steel wires, the textile membranes, joins the tectonic of the structural masses. It is, however, always a question of combinations of materials of very different nature. But here is one material which can itself suit, either to express the lightness, or to transmit the reassuring sense of the firmitas. Just the material of more ancient building tradition, the stone, can be used today on one side traditionally in the structural elements, on the other in innovative way in slabs and panels of high lightness or even translucent.
