An openBIM–openGIS framework for route-aware embodied-carbon assessment in public building procurement

Abstract

Urban construction supply chains contribute substantially to greenhouse-gas emissions and logistical inefficiencies, partly due to fragmented digital workflows between Building Information Modelling (BIM) and Geographic Information Systems (GIS). This study introduces an openBIM–openGIS integration framework for route-aware embodied-carbon modelling by coupling BIM-based material quantity data with GIS-derived transportation networks. Conceptually, openBIM provides the material-demand layer, openGIS provides the spatial-network layer, route-aware modelling links supplier locations to network distances, and embodied-carbon accounting quantifies route-specific A4 impacts. The approach replaces static distance assumptions in conventional BIM–LCA procurement models with network-derived routeing data generated through a newly developed Open-GIS routeing tool. The containerized tool, available as a web application and programmable API, automates multi-origin supplier-to-site routeing using open geospatial datasets and API-driven services. Beyond embodied-carbon analysis, the API architecture can support integration with software development, data-driven modelling, and decision-support workflows. A Toronto public-building case compares a conventional 100 km baseline with supplier-specific heavy-goods-vehicle routeing. The route-aware model increased estimated A4 emissions by 17.8%, revealing sensitivity to supplier geography and road-network connectivity. These results indicate that fixed-distance assumptions can mask spatial variation in construction logistics. By improving transparency, reproducibility, and spatial specificity, the framework supports evidence-based low-carbon procurement decision-making within construction management.