Carbon Reduction Potential of Modular Bathroom Systems in the A1–A3 Life-Cycle Stages

Efforts to reduce greenhouse gas (GHG) emissions across various sectors are on-going to overcome the global climate crisis induced by global warming. The construction sector is a significant contributor of GHG emissions due to the complexity of its diverse processes and the extensive use of various materials. Consequently, simplifying construction processes and adopting low-carbon materials and processes through the rigorous review of material carbon footprints is urgently needed. This study focused on bathrooms (wet areas), which are characterized by complex procedures, the use of diverse materials, and the significant carbon emissions and material waste often resulting from high defect rates. We conducted a comparative analysis of the carbon reduction effects between the conventional wet construction method and the modular construction method specifically for bathroom construction. The analysis involved selecting materials, assessing their suitability against performance standards using a mock-up evaluation, and evaluating the construction applicability of modular bathrooms. Furthermore, through a Life Cycle Assessment, it was confirmed that the selected materials and the modular construction method could significantly reduce carbon emissions compared to the existing wet construction method. The findings of this study provide a crucial direction for the expanded application and use of modular construction methods in future building projects.