Comparative Life Cycle Assessment of Topology Optimization and Generative Design for Sustainable Additively Manufactured Furniture

Sustainability is an increasingly important objective in design and engineering, yet the environmental implications of advanced computational design methods remain insufficiently quantified. This study examines the contribution of topology optimization to sustainable product development when applied exclusively to a product’s internal structure, while preserving external geometry, mechanical performance, and design intent. The furniture sector was selected as a representative case due to its significant environmental footprint and the strong role of aesthetic requirements within the design methodology. A gate-to-gate Life Cycle Assessment was performed to compare a conventionally designed stool with an internally optimized counterpart, both developed under the same design constraints and manufactured via Fused Deposition Modeling using Carbon Fiber-reinforced PETG (CF-PETG). The results indicate that computational strategies can reduce material waste by 57.8% to 90% compared to traditional subtractive methods. However, these benefits may be partially offset by increased energy demand during additive manufacturing due to geometric complexity. An additional comparative assessment involving generative design demonstrates that alternative computational strategies can achieve more balanced trade-offs between material efficiency and manufacturing energy, supporting sustainability while respecting design methodology constraints.