Technological innovation and architectural design represent an ever closer union that sees the building envelope as a meeting element of these two components. The skin of architecture loses the function of pure cladding, becoming an interface through which the building receives and transmits information in an "intelligent" manner. The door for the 4.1 project makes this technology its own and is built like an architecture. The cannulated aluminum internal structure can be dressed with a wooden plank finish or with a lacquered counter panel. A dress meant to protect but also express.