Large-scale fire testing remains the most straightforward route to gain knowledge about the fire spread mechanism and other heat and mass transfer characteristics under various conditions. However, these assessments are costly, destructive, and often impossible to conduct due to many practical constraints. Even when a large-scale test is performed, it is typically carried out on ideal constructed systems. In practice, the actual conditions and scenarios may be vastly different from the testing standards. The application of computational fluid dynamic (CFD) modelling on building fires has become increasingly popular due to the rapid advancement of numerical methodologies and computational power. The heat and mass transfer, as well as the conservation of gas species and smoke particulates, can be aptly computed by CFD models with quality meshing and a good selection of numerical models. Therefore, numerical simulations based on CFD modelling are a cost-effective tool to bridge the knowledge gap and explore the system sensitivity to some of the parameters such as dimensions and material selection. The developments of effective numerical tools to address the needs of fire safety assessments will be beneficial to the building industry and government authorities, providing a complementary design tool for fire safety engineering design and fire investigation studies.