Sustainable building, use of local materials, responsible use of soils, re-use, adaptability to climate, are all concepts that became worldwide part of the vocabulary of contemporary architectural design since the energy expenditure in the construction sector has proved to be of such magnitude to be unsustainable in the medium and long term. Yet these are the basic concepts that have always been considered as being of vital importance in vernacular and spontaneous building throughout the world. The great variety of shapes, typologies and materials used were always the optimal response to local social-, weather-, religious conditions and example of essential and efficient use of resources. Buildings were, throughout history, mostly set according to three basic principles: climatic-environmental, socio-cultural and socio-economic. The specific local variations of each of the three principles have generated buildings able to fully respond to the identified needs. This contribution aims to highlight how the lessons taught by vernacular architecture can inspire contemporary architecture and how a reinterpretation of the vernacular heritage can become our challenge for the future.