Decarbonizing precast concrete building components: Cradle-to-site carbon modeling and optimization, explainable machine learning, and a transportation efficiency index

2026-04-17T03:33:23+00:00

Reducing carbon in prefabricated buildings demands component-scale evidence, yet most assessments remain confined to factory production and provide limited, non-transparent guidance on how transportation and on-site installation decisions reshape emissions. This study delivers a consistent framework for quantifying and predicting emissions from the production, transportation, and installation of precast concrete components. It explores the concept that integrating coordinated design standards with logistical planning leads to considerable reductions in cradle-to-site emissions. The framework contributes: (i) a tri-stage system boundary; (ii) a machine-learning plus explainable-AI (XAI) model for transport coupled with a new Transportation Efficiency Index (TEI), defined as delivered component volume-distance per unit CO₂e; and (iii) joint optimization of design standardization and logistics parameters. Empirical data were obtained from a prefabrication plant in Tehran, Iran (156,000 m² footprint; 300,000 m³·yr⁻¹ capacity), including 411 daily energy/resource records, bills of materials and mold-use logs, 408 manufactured components, and matched delivery/installation activities. Gradient-boosted trees yield high predictive accuracy (coefficient of determination R²= 0.99 for production and R²= 0.97 for transportation; mean absolute percentage error MAPE < 6%), while XAI identifies component volume, design standardization, route distance, and truck utilization as dominant drivers; materials account for ~91–98% of production emissions and mold amortization falls from ~9% to <3% when standardization exceeds 0.90 and reuse surpasses ~60 cycles. Scenario optimization improves TEI by ~25% and reduces combined production-to-installation emissions by ~20–30%, providing actionable guidance for manufacturers, contractors, and policymakers seeking low-carbon prefabrication supply chains.

An integrated framework for a sustainable hotel complex in Ghazni: A climate-responsive, culturally-attuned model for arid climates

2026-05-09T02:56:03+00:00

This study addresses the critical need for sustainable hospitality infrastructure in regions with distinct climatic and cultural contexts, focusing on Ghazni, Afghanistan (AFG). It answers two primary research questions: (1) What quantified energy and carbon reductions can be achieved by integrating vernacular passive strategies with active renewable systems in a hotel model for Ghazni? (2) What design parameters ensure cultural relevance, technical feasibility, and local adaptability? The study develops and evaluates an integrated, context-specific Sustainable Hotel Model (SHM) through a mixed-methods approach, combining socio-technical surveys (N = 250), expert interviews (N = 24), and building performance simulation using Autodesk Revit (BIM) and EnergyPlus. A household survey revealed strong public endorsement for sustainability (76% priority) and solar energy (94.95% support), alongside significant gaps in current hotel practices (77.78% perceived no energy efficiency (EE) measures). Expert interviews informed a four-pillar design framework comprising 65 principles across the Socio-Cultural, Economic, Environmental, and Technical domains. Simulation results demonstrate that the proposed SHM achieves a 14.68% reduction in total site energy consumption, a 20.66% reduction in cooling demand, and meets 91.6% of its annual electricity demand via on-site solar photovoltaic (PV) systems. Lifecycle carbon assessment shows a 73.3% reduction in total carbon emissions, driven primarily by an 80.3% reduction in embodied carbon through local, low-embodied-energy materials. The study concludes that authentic sustainability in such contexts requires a synergistic system where high environmental performance is achieved through, not at the expense of, cultural preservation and economic vitality. This research provides a simulation-evaluated, replicable blueprint for decarbonizing the hospitality sector and promoting sustainable regional development in arid, culturally significant regions.

Building Engineering

Decarbonizing precast concrete building components: Cradle-to-site carbon modeling and optimization, explainable machine learning, and a transportation efficiency index

An integrated framework for a sustainable hotel complex in Ghazni: A climate-responsive, culturally-attuned model for arid climates