•The finite element method can reliably capture heat exchange between embedded walls and the ground given sufficient attention is paid to mesh refinement and the assessment of key parameters.•For experimental case studies careful consideration should be given to the characterisation of such geostructures, their constituent materials and surrounding environment to ensure the heat transfer processes are understood.•The thermal properties of the wall elements are at least as important as, and in some cases more so than, those of the ground in determining the heat transfer potential.•Wall geometry in terms of the height of wall exposed to any internal space relative to the height of the wall panel height and the wall thickness have been revealed to have an important influence on heat exchange potential. A number of operational cases exist where embedded retaining walls, used in the construction of underground spaces such as basements and shallow tunnels, have also been utilised as ground-heat exchangers in shallow geothermal energy systems. These are complex structures in terms of their geometry, the surrounding temperature field and boundary conditions, and there are currently no methods to assess their heat exchange capacity in a simple and expedient manner. This contribution uses the finite element method to validate the use of the method in predicting heat flow for this application and then, to assess the influence of wall and excavation geometry in the heat exchange process. The influence of the soil and wall thermal conductivity is shown to be quasi-linear with the latter showing the greatest influence on peak heat exchange. The work identifies a geometric parameter - the ratio of excavation depth to total wall panel depth, H/L which in combination with the wall thickness (D), provide a consistent and simple means by which the heat exchange potential can be estimated, for a given set of wall and soil thermal properties and boundary conditions.