Enabling a Material Re-Use Workflow with LLM-Extracted Metadata for Circular Construction

Authors

Peter Waldert (Graz University of Technology), Lukas Gschweitl (Graz University of Technology), Benedikt Kantz (Institute of Visual Computing, University of Technology Graz), Matthias Lang-Raudaschl (Graz University of Technology), Milena Stavric (Graz University of technology), Tobias Schreck (Graz University of Technology)

Abstract

Construction accounts for 50% of European material consumption, 36% of EU waste, and 39% of global energy-related greenhouse gas emissions, making material reuse a pressing climate priority. Reclaimed components exist in abundance, but reuse remains impractical within typical project schedules: available stock is scattered across dozens of fragmented Digital Material Banks (DMBs) - web portals that list components salvaged from demolition or refurbishment - and the data on those platforms is frequently incomplete; critical attributes are buried in PDFs rather than exposed as searchable fields. Developed in close collaboration with practising architects, ReUseBIM addresses both obstacles. A dashboard aggregates listings from DMBs into a single metadata-searchable view and provides Building Information Modelling (BIM)-ready Industry Foundation Classes (IFC) files for drag-and-drop into any BIM-capable software, helping architects to efficiently search, compare, and select reclaimed components without leaving their existing workflow. Our enrichment pipeline uses an Large Language Model (LLM) to extract missing attributes from attached documents, presenting each detected value to the architect for confirmation before writing it into the IFC file. Together, these make specifying a reclaimed component as straightforward as specifying a new one.