he function of façades in architecture and the big portfolio of protective layersdeveloped by nature (skin, membranes, shells, cuticles) share several similarities. Innature, skin is the largest organ that protects the body from external invaders. Skinis a multitasker performing several functions critical for health and well-being oforganisms. Built from several layers, skin protects, regulates, controls, absorbs,maintains, senses, and camouflages. The analogies between functions of thebuilding façades and animal skin are presented in Fig.1.1. Building façades partlydefine architectural characteristics of structures and act as a shelter and space forhuman activity (Gruber and Gosztonyi2010). They provide UV, moisture, andthermal defence, as well as protection from dirt, micro-organisms, and radiation.Façades communicate by transferring information—they are capable of exchangingand storing energy, heat, and water.Since thefirst buildings were constructed, façades have been separating twoenvironments: external and internal.