In the wake of the 2030 Agenda, many strategies have been implemented globally, in order to fulfill its goals. Amongst these, reaching sustainability and low environmental impact of construction materials is a greatly important topic, mostly carried out by the adoption of recycled and low embodied energy construction materials. Based on such premises, the ITER project aims at testing and optimizing the mix design and the production process of sustainable raw earth-based plasters stabilized using byproducts from the agriculture supply chain (natural fibers) and stone supply chain (marble dust obtained from stone sawing and processing).The aim is to reduce manufacturing impacts by finding new uses for materials that are considered waste by an industry, but that can be a valid resource for another one. The use of unprocessed raw earth in substitution of energy-demanding cement mortars and other local materials is the key to a sustainable product. Furthermore, the use of marble dust and waste plant fibers, represents a concrete example of how the application of industrial symbiosis can transform an environmental problem into an opportunity. The plaster mixes thus designed were tested in order to also guarantee compliance with the required mechanical and physical performances. Results in terms of density, shrinkage, flexural and compressive strength and capillary absorption are presented in this paper. Such results are a preliminary assessment which will serve as a starting point for the subsequent phases of the ITER project.