Soft storey is generally present at the entrance (bottom) floors of the buildings. Because entrance floors of the buildings are utilized as bank branches, storeys, restaurants, offices, car parking and the upper storeys are used as dwellings. Soft storey is an irregularity which affects the behavior of a construction during a quake and also increases the construction costs. Such features are highly undesirable in buildings built in seismically active areas; this has been verified in numerous experiences of strong shaking during the past earthquakes. For this reason, soft storey should be avoided as much as possible. In case it is necessary, irregularities can be eliminated by increasing the lateral rigidity of this storey by putting up additional walls between single structural elements on the soft storey; placing diagonals between the columns and shear walls; increasing the rigidity of the soft storey by increasing beam-column size of the soft storey.