Life cycle sustainability assessment for modular construction – A proposed conceptual framework

Abstract

Offsite construction (OSC) is increasingly recognised as a viable alternative for conventional in-situ construction. Modular construction (MC) is one of the most advanced and efficient OSC methods in the construction industry. Even with the distinctive benefits offered by MC, it is imperative to investigate the sustainability performance of MC to understand the trade-offs with traditional construction. Life cycle sustainability assessment (LCSA) is a tool that integrates the three pillars of sustainability from a life cycle perspective. At present, the most common method is to consider the LCSA as a sum of life cycle assessment (LCA), life cycle costing (LCC), and social LCA (S-LCA). However, studies that have employed the LCSA methodology in assessing MC are still lacking in the literature. Relevant literature still lacks comprehensive framework guidance to conduct LCSA of MC. Thus, this paper aims to propose a conceptual framework that integrates the triple bottom line (TBL) of sustainability to assess the sustainability performance of MC using LCSA. The publications acquired from the keyword search analysis were reviewed to develop the conceptual framework by identifying the key factors and challenges to the LCSA. The framework integrates the methodological steps, findings, and gaps related to LCSA discovered from the literature survey. The results show that the LCSA goal and scope should be defined properly to address the complications from the methodological differences of the TBL of sustainability. The proposed framework offers insight to academia and construction industry practitioners about the holistic investigation of the sustainability performance of MC.