Modular Construction and Climate Change Mitigation: Lifecycle Carbon Impacts of Prefabricated Housing Systems

Abstract

The construction sector accounts for approximately 38% of global energy-related carbon dioxide (CO₂) emissions, yet evidence on whether modular and prefabricated housing genuinely reduces whole-life carbon remains fragmented and context-specific. This paper systematically synthesises 57 Scopus-indexed studies (2012–2026) on the lifecycle carbon performance of prefabricated residential buildings, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidance. Across the evidence base, prefabricated systems reduced construction-phase embodied carbon by 10–45% relative to conventional alternatives, with the largest savings associated with timber-based systems, high prefabrication rates, and short transport distances; module reuse at end-of-life recovered up to 30% of initial embodied carbon, and design for disassembly avoided up to 20% of demolition-phase emissions. Reported reductions, however, varied substantially with regional electricity mixes, system boundaries, and lifecycle assessment (LCA) assumptions. The paper's principal novelty is the Carbon–Context Alignment Framework (CCAF), an inductively derived conceptual model proposing that the climate efficacy of prefabrication is determined by the simultaneous alignment of four contextual dimensions: material carbon intensity, grid carbon factor, policy and regulatory environment, and social housing scale. An illustrative application demonstrates how the CCAF can be operationalised as a diagnostic tool for policymakers, developers, and designers seeking to configure prefabricated housing programmes for maximum climate mitigation benefit across low-, middle-, and high-income settings.