Housing-service conditions and urban mining potential of single residential buildings: insights from material stock–flow analysis in the Philippines

Single residential buildings (SRBs) are a major component of housing, yet their material stocks and flows remain insufficiently quantified in data-scarce countries. This study applies a bottom-up dynamic material stock–flow analysis that integrates material intensities derived from construction documents, statistical data, and remote-sensing datasets for the Philippines from 2008 to 2023. Results show that the estimated annual inflows increased from 19 million metric tons (Mt) in 2009 to 34 Mt in 2023, while the estimated outflows increased from 4.7 to 5.6 Mt. Cumulative inflows and outflows reached 383 and 76 Mt, respectively, resulting in approximately 5921 Mt of in-use stock in 2023. In-use stocks were dominated by mineral- and masonry-based materials. Regional indicators also show that housing-service conditions of SRBs are multidimensional, reflecting distinct aspects of material concentration, population, dwelling-scale accumulation, and active occupancy, while stock-based urban mining assessment identified concrete, masonry materials, and metals as priority streams.