Floating columns on cantilever projections of beams, or on transfer girders affect the behaviour of multi-storeyed buildings during an earthquake. the present study investigates the effect of floating columns on the seismic forces in the supporting members, in a typical reinforced concrete mid-rise building. First, the computation model of a reference building with an open ground storey, was developed. In the first series of analysis, variants of this building were modelled with floating columns along the periphery, and supported on cantilever projections of the beams in the first floor. the corresponding columns in the ground storey were offset inwards to reduce the footprint area at the base of the building. In the second series of analysis, variants of the reference building were modelled with transfer girders supporting the floating columns. From the analyses of the models, forces developed in the ground storey columns and the first floor beams were compared with those of the reference building. It was found that the cantilever spans and transfer girders supporting the floating columns develop very high shear force and bending moment under gravity loads, and in combination with earthquake load. the effect of floating columns is also evident in the high shear force and bending moment in the columns of the ground storey. the increase in the vulnerability of the columns is pronounced when the additional effect of open ground storey is considered.