A social life cycle assessment model for building construction in Hong Kong

Social life cycle assessment (S-LCA) is a relatively new technique that is under rapid development. To further improve the reliability of S-LCA, more case studies and methodologies are of paramount importance. This study aims to develop a S-LCA model for building construction projects in Hong Kong, namely, the Social-impact Model of Construction (SMoC). In this paper, a social life cycle impact assessment (sLCIA) method is developed and a case study of a building construction project in Hong Kong is performed. The development of SMoC is composed of three stages. Stage one strives to establish the sLCIA method which includes the characterization, normalization and weighting. In stage two, a questionnaire survey is conducted to collect the weighting factors and to unveil the social impacts of on-site construction practices. Based on that, the SMoC model which consists of a set of functional worksheets is built. In stage three, a case study following the four-phase structure of S-LCA suggested by the UNEP/SETAC guidelines is conducted. Of the selected subcategories, local experts believed that health and safety (worker) is the most important social aspect. The questionnaire survey also suggests that the environmental-friendly on-site construction activities as identified in this research are beneficial to the society in general. However, adoption of precast concrete components can lead to negative impacts on fair salary and local employment, since the precast concrete is normally produced outside Hong Kong. The case study demonstrates that the studied project has positive social impacts in general, while the construction stage performs better than the material stage. The sensitivity analysis indicates that inclusion of environmental-friendly construction practices can significantly improve the social performance of the studied building construction project. The developed SMoC model and the case study should provide a comprehensive framework of S-LCA for building construction in Hong Kong. Despite being the first attempt of S-LCA in Hong Kong, the results help inform the local industry the social performance of their construction projects from a life cycle perspective.