Computational workflow integrating differential growth and robotic WAAM for fabrication-aware architectural design: a furniture-scale demonstrator

Purpose This study develops a fabrication-aware computational workflow for architectural applications using Wire-and-Arc Additive Manufacturing (WAAM). It addresses the gap in methods that integrate computational geometry with fabrication constraints, aiming to produce geometries that are both generative and manufacturable. The research formalizes a parameter-driven design-to-fabrication framework bridging computational modeling and robotic metal deposition, providing a transferable methodology that can inform applications beyond prototype-scale fabrication while preserving architectural design intent. Design/methodology/approach A computational workflow using differential growth principles in Grasshopper generates iterative geometries evaluated against fabrication criteria such as deposition stability, curvature continuity and robotic feasibility. Contour segmentation and toolpath simulation are incorporated as active design considerations rather than post-design checks. Designs are iteratively filtered and prepared for WAAM fabrication. The workflow is demonstrated through the production of an aluminum prototype, illustrating the translation of computational models into robotic metal deposition while embedding manufacturing constraints within the design-to-fabrication process. Findings The workflow integrates fabrication constraints within computational geometry generation, producing geometries that were assessed as both expressive and manufacturable. The WAAM-printed aluminum prototype demonstrates the practical translation of digital models into robotic deposition, with deposition continuity and self-supporting behavior observed during fabrication and inspection. Iterative evaluation supported geometry selection while maintaining generative flexibility. The study establishes a structured, parameter-driven design-to-fabrication workflow and identifies requirements for further quantitative validation and larger-scale architectural applications. Research limitations/implications The study is demonstrated through a furniture-scale prototype and does not include quantitative mechanical testing, comparative performance benchmarking or architectural-scale validation. Future research should investigate structural performance, process monitoring, thermal management, robotic reach, assembly interfaces and scalability for architectural applications. Practical implications The proposed workflow provides a structured approach for designers and researchers to consider fabrication constraints during computational geometry development rather than only after design completion. Iterative geometry filtering and toolpath simulation can help identify potential fabrication issues before physical production. The demonstrated furniture-scale application provides a practical basis for exploring similar workflows for customized metal components and architectural elements, while larger-scale implementation would require additional structural, robotic, thermal, logistical and economic evaluation. Originality/value This study embeds fabrication constraints directly within generative geometry, integrating differential growth with WAAM to establish a structured, parameter-driven design-to-fabrication workflow. The physical fabrication of an aluminum prototype demonstrates the translation of computational geometry into robotic metal deposition under fabrication constraints. The contribution lies in formalizing a reusable workflow that connects generative design, fabrication-aware filtering, toolpath preparation and robotic fabrication, while identifying a methodological basis for future investigation of larger-scale architectural applications.