Regional end-of-life embodied carbon emissions of wood-frame housing: A hybrid-parametric assessment of single-family houses in Canada

The aging wood-frame single-family housing stock in North America represents a major future source of demolition waste and a substantial supply of recoverable wood materials. However, the embodied carbon implications of alternative end-of-life (EoL) strategies remain poorly understood at the regional scale due to limitations in temporal resolution, empirical validation, and carbon pathway characterization. This study develops a hybrid-parametric modelling framework that integrates historical construction eras, material flow analysis, the 9R circular economy hierarchy, and life cycle module-based carbon accounting (C1 D) to assess 81,598 single-family houses in Vancouver, Canada. The framework incorporates uncertainty through Monte Carlo simulations and is validated against four real-world deconstruction projects, demonstrating its capability to represent both material flows and carbon outcomes. The modelled wood generation (155.9 kg/m 2 ) and diversion rate (90%) fall within the observed ranges (120.8–179.0 kg/m 2 and 84–99%). Results show that EoL scenario selection has a substantially greater influence on embodied carbon performance than building age. Conventional demolition generates average net emissions of 9.39 kgCO₂e/m 2 . Moderate deconstruction (75% diversion) reduces this to 3.12 kgCO₂e/m 2 (−67%), whereas high-diversion pathways achieve net savings of 1.23 and 6.92 kgCO₂e/m 2 at 90% and 95% diversion. Structural lumber represents the largest recoverable material fraction and the primary source of mitigation potential. Sensitivity analysis identifies labour intensity, recovery efficiency, and allocation among reuse, repurposing, and recycling pathways as the dominant determinants of carbon outcomes. Biogenic carbon assessment further demonstrates that circular strategies primarily alter the timing and distribution of carbon flows through material substitution and emission deferral rather than permanent carbon sequestration. A critical circular economy gap is identified between diversion quantity and recovery quality, as similar diversion rates can result in substantially different carbon outcomes depending on the value retained from recovered wood. These findings highlight the need for wood-specific recovery targets and carbon-based performance metrics that prioritize high-value material retention over diversion quantity alone to maximize embodied carbon mitigation and circular economy benefits.