Effects of Lean Construction on Sustainability of Modular Homebuilding

TLDR

Construction activities heavily impact the environment, human health, and economy, and while sustainable homebuilding is achievable through practical innovations, its adoption is hindered by higher initial costs from worker learning curves and poorly defined processes. The study proposes using lean construction, particularly the kaizen tool, to overcome barriers and achieve sustainable modular homebuilding. The authors employ multiple case studies, each focusing on a single sustainability dimension, to demonstrate lean construction’s impact on environmental, social, and economic outcomes. Lean construction cut material waste by 64%, eliminated key safety hazards, and reduced production hours by 31%, illustrating its positive environmental, social, and economic effects on modular homebuilding.

Abstract

Construction activities and the built environment have an enormous effect on the environment, human health, and the overall economy. Sustainable homebuilding in all three dimensions of economic, environmental, and social effects is attainable through practical innovations and technologies. However, the greatest barrier to the widespread application of sustainable homebuilding is the higher initial costs largely attributable to the learning curve of workers building with these practical innovations and technologies, and the added cost resulting from ill-defined construction processes. To address these challenges and reach the ideal of sustainable construction, this paper proposes the use of lean construction as a viable and effective strategy, in particular the lean tool kaizen. This paper uses several case studies to showcase the effect of lean on the triple bottom line of sustainability in modular homebuilding. Each case study highlights one dimension of sustainability. Lean construction resulted in a significant environmental effect by reducing material waste by 64%, a significant social effect by reducing or eliminating key safety hazards of excessive force, poor posture, and struck-by, and a significant economic effect by reducing production hours by 31%. Findings from this research will contribute to a better understanding of the effect of lean on homebuilding sustainability and will promote lean and safe building techniques in modular homebuilding.