Stone materials in sustainable housing architecture

In the field of sustainable building development, stone materials hold a misleading role. In fact, if on one hand, stone shares with wood and earth the supremacy as the natural material par excellence, on the other, quarries, where the production process takes place, are often held responsible for serious environmental damages. At production level, in order to find answers to the problem, research has for some time been addressing at least three different courses: • Reducing production waste by improving extraction and cutting techniques; • Recovering above-said waste by using it in composite materials; • Reducing the amount of stone to be used by diminishing the thickness of building elements. In all three cases, the environmental aim is associated with a coincident reduction of costs, characteristically high for this material. Nonetheless, in all three cases, the necessary investments tend to counterbalance the expected economical advantages. On the contrary, at planning level, one often notices a lack of a thorough knowledge of production problems. Therefore, even if today the issue of sustainability is topical, stone architecture tends to take primarily into account the most superficial aspects. In fact, the renewed interest in stone, emerged in the seventies and eighties through “filmy” coatings, has now been associated with a greater attention towards “matter” shapes. This resulted in rough-surface coatings and, often, also in a revival of stone supporting masonry, always exposed. On the strength of these considerations and also in view of the fact that economical, technical and social motives make housing privileged grounds for the application of building sustainability principles, this paper intends to: • Restore the “state-of-the-art” in the above mentioned development sectors, analysing the most recent products of the stone industry; • Examine architectural works that, owing to building choices and solutions, can be considered as more illustrative of the designers’ successful approach to the issues of this Congress.