Smart materials integrating conventional soft electronics e.g. sensors and actuators, are widely used in the building and wearable industries, contributing to the depletion of natural resources and having a vast environmental impact. In this chapter, a novel method using living fungi for the development of responsive materials for smart architectural and wearable skins is discussed. Living fungi composites exhibit remarkable self-sustainable properties: self-growth, self-repair and self-assembly. They present responsive capabilities to environmental, chemical and mechanical stimuli, allowing the implementation of sensorial fusion and decision-making. We inoculated hemp mat substrates with the fungus Pleurotus ostreatus and cultured until a coating of white mycelial growth was observed. We performed a series of laboratory experiments on the fungal composites, exposing them to various environmental, chemical and mechanical stimuli and we explored their communication protocols and smart capabilities. We found that living fungi composites employ precise responsive mechanisms by generating distinct electrical potential impulses in the form of spike events, presenting a promising alternative to conventional smart materials. The results open up new possibilities for the development of the next generation of smart materials for the building and wearable industries, allowing large-scale implementation and production.