Houses built or renovated with wood, earth, straw, or a wide variety of biological materials are proliferating in the Girona regions thanks to a unique ecosystem in Catalonia that brings together dissemination and training entities, architects, surveyors, and all kinds of sustainable construction professionals. It is a very well-connected network that helps, among many other things, to train self-builders, share experiences, resolve doubts, obtain labor, and find natural materials with a zero (or negative) carbon footprint.