The study of solid waste reuse and recycle for sustainable construction is attracting the attention of researchers and practitioners due to the low cost, the high availability and the potential properties of waste materials. This paper introduces a research aimed at analyzing the economic and environmental impacts of a sustainable construction material, i.e. an innovative green mortar. Such mortar was obtained from the reuse of the foundry sands of an Italian automotive company. The aim was to realize a sustainable product, proposing the reuse and the valorization of the wastage left over of a manufacturing process. In this paper, the characteristics of the green mortar as a cement aggregate replacement were investigated, together with the economic and the environmental impacts of such material. The methodologies adopted in this research include the Life Cycle Assessment of the green mortar and the cost-benefit analysis for the production process. The results confirm that the adoption of a circular economy-based management for the foundry sands would allow economic and environmental benefits for all the actors involved in the supply chain of the green mortar.