Prefabricated Buildings and Urban Energy Productivity: A Thematic Literature Review of Lifecycle Impacts, Construction-Phase Efficiency, and City-Scale Energy Efficiency

The evidence indicates that prefabricated and modular building systems can improve urban energy productivity, but the direction and magnitude depend strongly on system design, transport distance, and lifecycle boundary. At the building scale, prefabricated systems reduce whole-life energy use by ۷.۵۴% and carbon emissions by ۷.۱۷% relative to conventional cast-in-situ construction, while another lifecycle comparison reports a ۶.۷۶% reduction in GHG emissions for light-steel prefabrication and up to ۶۵% lower embodied impacts in some prefabricated configurations (S. Wang et al., ۲۰۲۴; Cai et al., ۲۰۲۳; Tavares et al., ۲۰۲۱). At the city scale, prefabricated buildings significantly improve urban green total factor energy efficiency, with innovation, industrial, and marketization effects identified as key pathways (Wang et al., ۲۰۲۴). The topic matters because urban energy gains from prefabrication are often assumed rather than jointly tested across operational, embodied, and system-level scales. Across the literature, construction-phase benefits are most consistent, including ۳۷% of traditional-building CO۲ emissions for prefabricated construction, ۸.۰۶% GHG savings in a cradle-to-gate office case, and ۴۴% shorter construction time in a modular housing system (Liu et al., ۲۰۲۲; Jayawardana et al., ۲۰۲۳; Romero Quidel et al., ۲۰۲۳). However, not all outcomes move in the same direction: higher prefabrication rates can increase total energy and carbon footprints in cradle-to-gate analyses, showing that logistics and material extraction may offset gains (Wang et al., ۲۰۲۴). The strongest implication is that prefabrication is best understood as a conditional energy-efficiency strategy rather than an inherently low-energy solution; future work should resolve how material choice, transport, and end-of-life recovery jointly shape city-scale benefits.

کلیدواژه ها:

prefabricated buildings ، urban energy ، energy efficiency ، cities ، modular construction