A breathing skin for buildings based on principles and methods abstracted from nature is presented. The skin reacts to changing conditions and influences the air pressure on the surface to perform a process of inhaling and exhaling. The system is created by a specific arrangement of a basic component, to utilize the space and the materials in an efficient way. The orientation and the geometry of the components allow deformations. These deformations are important to create a gradient pressure on the surface of the building skin, which results in sucking and expelling the air, which results in regulating the interior microclimates. Piezoelectric wires are used to generate the deformations. The rate of air-exchange is affected by the velocity of the component changing shape (deformation velocity). By developing this system we are not dealing with a separate ventilation system, but with an integral part of the building envelope which functions as a protective layer too.