Digital Product Passports for Circular Wood Construction: A Semantic Graph-Based Architecture and AI-Enhanced Services

This paper presents the design and implementation of a Digital Product Passport (DPP) architecture developed in the context of the Wood2Wood (W2W) project to enhance transparency, circularity, and regulatory compliance in the wood construction and demolition sector. The proposed system integrates heterogeneous product lifecycle data using a semantic graph database (GraphDB by Ontotext) that stores RDF triples aligned with domain ontologies, enabling rich SPARQL querying and knowledge graph enrichment. A modular backend built with Django exposes APIs for data ingestion, validation, and differentiated access control, while a web frontend developed with TailwindCSS and QR code-based product identifiers links physical wood elements to their digital records for both professional and public users. The paper demonstrates how this architecture supports material tracking, product identification, and data sharing across stakeholders, and abstracts these components into a transferable framework applicable to other sectors facing similar sustainability and Ecodesign for Sustainable Products Regulation (ESPR) requirements. Finally, the work outlines future extensions with AI-driven services, including an automatic summarizer and a Retrieval-Augmented Generation (RAG) chatbot tightly coupled with the graph database, to deliver interactive, personalized access to product information and further lower barriers to DPP adoption.