Open Ground Storey (OGS) buildings are prevalent in Indian urban environments to accommodate parkingat theground floor. However, the abrupt reduction in lateral stiffness at this level makes them highly vulnerable to seismic forces. TheIndian seismic code IS 1893:2016 prescribes a multiplication factor (MF) of 2.5 for the design of ground-storey membersinOGSbuildings without considering infill stiffness. This paper evaluates the applicability of this factor for low- to mid-riseOGSstructures using Equivalent Static Analysis (ESA) and Response Spectrum Analysis (RSA) in ETABS for four buildingheights(G+4, G+8, G+10, G+15) in Seismic Zone V. Infill walls were modelled as equivalent diagonal struts. The results showthat actualMF values range between 1.05 and 1.71, significantly lower than the code-specified 2.5, indicating that the provisionmaybeconservative for certain cases. Keywords Open Ground Storey, Multiplication Factor, Infill Stiffness, Seismic Performance, Equivalent Static Analysis, ResponseSpectrum Analysis.