Sandwich panels also known as concrewalls are made up of a non-structural insulation layer sandwiched in between two structural concrete layers connected by a shear connector. This technology is relatively new and the parameters affecting the properties of these panels are not well studied. In Ethiopia, suitable design aids, i.e., interaction diagrams for the design of these panels are not available. In this paper, the parameters affecting the load carrying capacities of sandwich panels are studied numerically using ANSYS software and later on, a computer application that generates interaction diagrams for these types of panels is developed. Major parameters studied numerically are shotcrete and polystyrene core thicknesses, effect of loading location and addition of vertical reinforcement bars. Increasing the shotcrete thickness from 25mm to 35mm and from 35mm to 45mm showed a 62.5% and 46.8% increment in the axial load carrying capacity. Increasing the EPS core thickness from 40 mm to 160 mm gave a 45.14% increment in the load carrying capacity. Addition of normal strength reinforcement bars showed only a small increment in the ultimate load capacity of panels loaded at panel centroid. For panels loaded at 60mm eccentricity addition of 16ϕ10 bars increased the ultimate load carrying capacity by 13.52%. Loading eccentricity was also another parameter that affected the ultimate axial load of the panels. As the load was applied further from the panel centroid, the observed ultimate load decreased due to an increment of bending moment with load eccentricity. Panels were also modeled with and without the polystyrene core and showed a significant difference in the deflected shape of the panels. From the observed relative vertical deformation and separation between the two wythes of the panels, it can be concluded that all the panels showed a near to fully composite behavior. A computer application that generates interaction diagram for different sections of wall sandwich panels is also developed using visual studio 2013. Key words: Expanded Polystyrene, Interaction diagram, schnell homes, Finite element analysis, sandwich wall