This paper builds on research from a project aimed at promoting the circular economy through processes based on low-impact materials derived from natural fibers. A methodology is developed to assess the economic, environmental, and social sustainability of alternative production scenarios, thereby supporting the ranking of options. Assuming the principles of Life Cycle Thinking and circular economy and the operational aspects of Life Cycle Costing (LCC), Life Cycle Assessment (LCA), Social Life Cycle Assessment (S-LCA) approaches normed by international standards, an integrated approach is proposed based on the construction of a joint Global Cost indicator. Attention is paid to harmonizing impacts assessed in their own units of measurement to arrive at a monetary indicator for summarizing and simplifying the prioritization of alternatives. As a result, the integrated Global Cost calculation methodology is presented to internalize social and environmental impacts, as well as economic ones, and to evaluate the sustainability of materials derived from primary and waste natural fibers.