Design concepts for adaptive multi-functional building envelopes

Modern architecture has developed innovative structural forms tending to separate the main supporting structural system from the interface between building and external or internal spaces. This concept is not only driven by aesthetics but represents a response to the needs of building economics and sustainability. Problems like energy saving and energy harvesting, comfort and acoustics can be efficiently faced by working on the characteristics of these interfaces, or envelopes, that therefore assume a separate entity combining structural requirements with other functional requirements. The paper is aimed at presenting the results of the researches recently conducted by the authors on the conception, based on free-form generating algorithms, of building envelopes that can be considered optimal with respect to different functional and structural criteria. Since the optimality conditions may change with the variation of the external/internal environment, the generation of these forms is obtained considering kinetic structural systems, in such a way that the shape of the envelopes can be switched from one optimal configuration to any other, thus creating adaptive systems. Shape optimization with respect to different conditions, like solar exposition, ventilation, acoustics etc. can be considered. The paper illustrates the main characteristics of the developed algorithms and shows some applications.