Background: Innovations in Construction 4.0 have now seen 3D printing positioned as a revolutionary technology for the manufacturing of structural elements, providing an automated process, using less material, and allowing for more flexibility in design. Eco-friendly building material for rural India. Although there is increasing use of eco-friendly construction materials in urban infrastructure, their practicality under real-world conditions in rural areas such as Osmanabad is less studied, where the climatic conditions, material scarcity, and participatory construction are essential. Objectives: The objective of this research is to assess the structural behaviour, the material sustainability, and the environmental performance, under a parametric framework, of 3DP walls and beams designed for the semi-arid context of Osmanabad. The main aims are load-bearing performance, flexural strength, heat behavior, and acceptance by stakeholders of printed systems. The research is framed in a community-based approach and, therefore, bridges the divide between high-tech fabrication and rural development objectives. Methods: A mixed-methods approach was employed. Locally combined basaltic aggregates, natural fibres, and recycled content were evaluated in cementitious-based mixes, which were tested with gantry-based 3D printers. Compressive, flexural, and bond strength tests, as well as the thermal gradient and curing conditions, were conducted on-site on the structural specimens. Computational modelling and topology optimization were supported by experimental validation, and stakeholder interviews offered a qualitative perspective. Results: It was found that SLBW demonstrated high compressive strength (~84 MPa) and predictable failure modes. For gapped structures (GLBW-3T, GLBW-5T), material savings, increased passive cooling up to 36%, and lower indoor temperatures of around 5.6°C were predicted. Fiber reinforcement improved structural integrity, and tailored curing cycles in rural employed day cycles guaranteed acceptable layer bonding. Conclusion: In conclusion, 3D printing can be technically feasible, material efficient, and operationally scalable in rural India, if it is embedded in local resources and practices and is participatory in approach. This study has demonstrated the importance of context-specific design, open-source construction processes, and collaborative training to disseminate advanced building technologies. In the future, this research will extend to the multi-storey system, long-term durability observation, and policy pathways for national rural integration.