In recent years, off-site construction has been significantly hyped as a viable solution for improving the sustainability of the construction industry. There is yet an approach to be developed that can utilise project-specific parameters to quantify the improvement in adopting off-site methods as opposed to conventional construction. This paper focuses specifically on modular construction as an off-site production system, where a decision support tool is proposed for contrasting conventional and modular construction methods based on selected sustainability criteria. The framework relies on quantifying certain measures of: i) social factors, including safety and noise pollution; ii) environmental factors, such as energy consumption, U-value of the building envelope and embodied energy; and iii) economic factors including time and cost of construction. Fuzzy logic, equivalent noise summation and algorithmic mapping are utilised to quantify the sustainable measures adopted. The indices utilised to showcase the possible comparison that can be made between construction methods, are up to the decision maker to decide upon. Realistic case studies, involving the construction of a granny flat and a school are used to demonstrate the applicability of the developed framework. The modular construction method was found to perform on average 21%, 52% and 60% better in terms of the measures adopted for social, environmental and economic costs in contrast with the conventional approach, for the cases considered.
