The use of prefabricated systems can alleviate the inadequate housing and skilled workers in most developed countries by expediting required construction time, reducing material wastage, decreasing the effect of weather impacts, minimizing unexpected costs, skilled labor dependence, and construction hazards. The full potential of prefabricated construction is yet to be realized in part due to most advancements being focused on its superstructure. The development of prefabricated substructures for lightweight buildings needs to consider the susceptibility to damage induced by the shrink‐swell movement of expansive soils causing significant global financial losses. Prefabricated substructures should have robust connections in discontinued regions to transfer forces and moments. Due to these issues, the aim of this study is to develop a connection for prefabricated raft substructures of single‐detached dwellings on expansive soils using a combined soil‐structure contact analysis and strut‐and‐tie model approach. The developed substructure system was validated using experiments and further investigated through numerical simulations. The developed prefabricated connection was observed to have satisfactory performance, potentially overcoming most construction limitations of conventional monolithic cast‐in‐place raft substructures, such as faster, safer, and more sustainable construction, while providing comparable strength and serviceability.