Abstract
The construction sector accounts for 37% of global carbon emissions and 40% of EU waste, driving policy initiatives toward decarbonisation and circularity. While biobased materials offer low-carbon alternatives, their limited adoption reflects systemic supply chain barriers rather than technical inadequacy. This research develops and applies a novel hierarchical supply chain mapping framework to identify strategic pathways for agri-crop biobased construction in Ireland, focusing on straw, hemp, and miscanthus. A novel four-stage supply chain mapping framework is developed integrating processing complexity and technological levels, applied in two national stakeholder workshops engaging multiple organisations across agriculture, manufacturing, construction, and policy sectors. Analysis reveals a range of potential supply chains spanning low-technology applications (bales, blown-in insulation) to industrialised products (boards, blocks, modular panels), with processing infrastructure and certification identified as critical bottlenecks. Irish workshops validate straw as the priority pathway, leveraging existing harvesting and chipping infrastructure for immediate market entry via timber-frame and modular systems, with staged expansion toward advanced fibre processing. Hemp presents high-value niche potential contingent on decortication capacity, while miscanthus offers long-term complementary benefits. Cross-cutting enablers include regional processing hubs, accelerated certification, public procurement, and coordinated policy frameworks. The novel hierarchical mapping framework and stakeholder-validated pathways provide a structured roadmap for translating agricultural by-products into viable construction resources, with applicability to similar regional and national contexts.