An expanded understanding of building performance acknowledges that all forces acting on buildings (climate, energies, information, human agents) are not static and fixed, but rather mutable and transient. This has serious consequences for the building envelope whose design must transcend its role as mere protective wrapper separating inside from outside.2 Building façades are increasingly developed as complex systems of material assemblies attuned to climate and energy optimization. With ever greater frequency, they are equipped with new performative materials, sensors, actuators and computerized intelligence that support automated dynamic operations and functionalities, such as regulating a building’s light, air and sound transmission, thermal transfer, and interior air quality. This façade-based equipment assists and even at times replaces functionalities otherwise performed by traditional building systems. As the building component most directly exposed to sun and wind, the envelope

is also the most effective site for innovations in energy savings and alternative energy generation.