Earthen culture heritage played a great role to revive interest for earth as a sustainable construction. The durability of earthen structure set a proof of its longevity. Nevertheless, earthen materials are sensitive to natural aggression from water, humidity, temperature. Moreover, due to climate change, buildings will be subject to new and unexpected environmental conditions. For new earthen buildings, their maintenance thus emerges as an issue at the early stage of construction planning to limit the risk of costly maintenance. The service life of earthen building will certainly be a key factor in the development of this technic in the coming years. The ambition of the DuReTerre project is to integrate a multi-scale approach to address a complex issue: the durability and repair of earth-based buildings. The DuReTerre project brings together an interdisciplinary team of architects, engineers, scientists and practitioners to develop methodology and tools to assess and improve the durability of earthen buildings. Patrimonial monuments from different French climatic zones, real scale prototypes as well as laboratory scale samples will be monitored to measure physical properties and correlate them with environmental data. Monitoring developments will benefit from an air-conditioned container where one side will be replaced by earthen walls and from instrumented walls in the EquipeX Sense City. Repair coatings and plaster will be designed with tailored additives limiting the water sensitivity and respectful of low environmental impact. New strategies of wall textured surfaces will be explored to limit rainfall degradations. Finally, the scientific understanding of the degradation and repair processes will allow the DuReTerre project to recommend relevant material characterizations and guidelines for maintenance and rehabilitation to manufacturers and practitioners.