The use of local materials is characteristic of most of millions of housing built before 1948 in France. These materials are not industrially processed and therefore lead to a significant decrease of grey energy consumption. However, due to lack of scientific knowledge, there is currently no clear recognized guidance for their set-up, or means of measurement to guarantee their performance. This lack commonly leads to apply renovation and construction methods which are unsuitable, and / or to prefer other building materials, environmentally less efficient, but benefiting from standardized testing procedure. In the best case, companies rely on their empirical knowledge of these buildings. Thus, the challenge of this proposal is to explore ways to measure and guarantee hygrothermal, mechanical and seismic performances of local materials and ensure their dissemination and development through an analysis of institutional conditions. To achieve this objective, we propose to identify and measure, through physico-mechanical modeling and experiments at different scales (laboratory, on site), the key parameters needed to describe the hydro-thermal behavior of buildings and seismic. In this context, we will study the impact of natural vegetable fibers additions on the behavior of the studied clay soils. The approach will be validated on the rammed earth and rough masonry constructions, which are the most representative of old buildings (before 1948). Ultimately, PRIMATERRE project will allow the development of design guidance and training modules.