Abstract
Despite the well-defined and established social factors and processes influencing project sustainability performance in the design and planning stages of construction projects, these factors and processes are at best qualitative in nature and could not be directly applied to measure quantitatively the qualitative impacts of the project on society. Thus, this paper proposes a quantitative model that uses an efficacy index to determine the actual efficacy level of the social sustainability of a construction project during the pre-construction stage. The model development required determining the factors that influence the social sustainability efficacy of a construction project, which was done through a methodical review of literature as well as using an expert-based approach. Construction projects can now be assessed and categorised based on their social sustainability efficacy evaluation scores. The evaluation scores obtained from the model indicate the social sustainability performance rating for the project, which would seek to highlight areas seeking improvement and improve the project's overall efficacy in a social context. Above all, this study introduced a different technique that attaches high significance to project stakeholders, users, workforce and local communities in order to attain sustainability in construction projects.