The construction industry faces numerous challenges, including environmental sustainability, high material costs, and a shortage of skilled labor. Modern technologies enabling digital fabrication present opportunities to reduce raw material consumption and waste generation. Among these, 3D printing technologies offer distinct advantages over traditional construction methods, particularly in handling complex geometries. However, the significant environmental impact of cement in 3D printed concrete, due to its high rheological and printability requirements, remains a concern. This study introduces a novel application of 3D printed permanent formwork in the construction of a winder staircase, assessed through an environmental Life Cycle Assessment (LCA) from cradle to gate. By comparing the environmental impacts of various construction materials and processes, the study highlights the comparative advantages and disadvantages of conventional methods versus 3D printing. The LCA results reveal that traditional production methods, particularly those using plywood formwork, exhibit higher environmental impacts. In contrast, timber formwork performs better than most 3D printed mixtures in terms of Global Warming Potential (GWP), Acidification Potential (AP), and Abiotic Depletion Potential (ADP). The findings of this study underscore the potential of additive manufacturing for sustainable construction, particularly through the use of low clinker cement in 3D printed formwork, offering a promising pathway towards reducing the environmental footprint of construction activities.