Failure of Open Ground Storey (OGS) buildings in the past devastating earthquakes like Bhuj, in India (2001) has urged the designers to carry out seismic evaluation of existing buildings and design the new buildings to withstand major earthquakes without collapse. Pushover analysis is the most commonly adopted analytical approach for seismic performance evaluation, the accuracy of which lies in suitable modeling assumptions made. In this paper, an effort is made to arrive at a definite modeling strategy to be adopted for the typical OGS building system while performing Nonlinear Static Pushover (NSP) analysis. Three building models representing the lateral stiffness of the building were considered, namely OGS bare frame (model 1), OGS within fill stiffness consideration in the upper storeys (model 2), building with infill stiffness consideration in the upper storey's and modeling additional infill stiffness in the corner bays of OGS (model 3). Lateral load analysis was considered for two cases, namely ESA (Equivalent Static Analysis) and RSA (Response Spectrum Analysis). For modeling the lateral load and nonlinear hinge properties, four scenarios were considered, scenario-1 with ESA load pattern and default hinges, Scenario 2 – RSA and user defined hinges, Scenario 3 – ESA and user defined hinges, and Scenario 4 - RSA with user defined hinges. The findings of the study revealed that the commonly adopted “model 1 – scenario 1” criteria results in an inaccurate prediction of performance levels of demand earthquake. Amongst the three models studied, model 3 shows the highest base shear by about two times and lowest roof displacement (60%) compared to bare frame and hinge status in case of scenario 1 is overestimated compared to scenarios 2 to 4. Therefore, model 3-scenario 4 is a better modeling strategy among the three models studied.