A Multi-Level Digital Passport Architecture for Emerging Regional Value Chains: Batch-Level Passports for Agro-Waste-Based Construction Products

Under the Ecodesign for Sustainable Products Regulation, the Digital Product Passport (DPP) is set at model, batch or item level in line with the traceability practice of each value chain. Emerging value chains, such as those of agro-waste-based construction products, connect actors from different sectors and require upstream data to be checked and transferred to the product passport. This study proposes a multi-level passport architecture in which a Digital Material Passport (DMP), associated with each residue batch, records origin, legal status, handling and measured properties, and is linked to the product DPP. The architecture was applied in Emilia-Romagna, Italy, to six agricultural residues, three of which feed five lime-based product models at Technology Readiness Level 3–4: a screed, two blocks and two panels. Screening identified seven batch parameters to verify before production. For the three residues used, producers documented 15 of 42 attributes, the laboratory 11, and 16 remain to be supplied; legal status was documented for one batch, as biomass fuel. Half of the DMP data remained within factory production control as acceptance checks; the other half were transmitted to the batch-level DPP as composition, bio-based content, origin and legal status of inputs, and embodied carbon.