Benchmarking the sustainability of concrete and steel modular construction for buildings in urban development

Abstract

The modular approach has been increasingly adopted for building projects. However, few previous studies investigated the performance of different modular construction systems and their impacts on urban development. This paper aims to contribute to a more systematic understanding of modular construction for buildings in high-rise high-density urban environment, through measuring the sustainability of both concrete and steel modular construction. The measurement was conducted using two real-life modular building projects in Hong Kong covering 11 indicators in environmental, social, and economic sustainability. Results reveal that modular construction significantly outperforms the conventional practice, e.g., 46%-87% of waste reduction thus reducing the burden of urban waste disposal. Nevertheless, performance of the steel modular system varies from the concrete one, e.g., being 40% faster thus more suitable for emergency project delivery, but 20% more of electricity consumption. From the discussion, eight system boundaries were identified for dialectical sustainability benchmarking, e.g., density boundary to indicate the project context; and systematic strategies were proposed for sustainability enhancement, e.g., design for circularity for temporary modular facilities. The paper should facilitate the selection of suitable modular systems by demonstrating the sustainability of different modular construction systems and contributing dialectical thinking to construction performance measurement.