Emissions-based options appraisal for modular building foundations: a case study

A study was undertaken to evaluate the embodied greenhouse gas emissions of four different design options for the foundation of a residential modular building in the East Midlands, UK. The assessment considered the embodied carbon dioxide equivalent of material production (without and with Portland cement replacement using ground granulated blast-furnace slag), transportation, construction works (such as soil excavation) and plant usage on site and off site. The findings indicated that helical piles and reinforced concrete slabs supported with expanded polystyrene were the most sustainable options (in terms of embodied emissions) compared with conventional strip and pad foundations. This study provides valuable insight into considerations and constraints that may arise when evaluating the sustainability of modular building foundations. It offers practical guidance for decision makers in the modular construction sector seeking to mitigate the environmental impact of their geotechnical design.