Earthquake is a very important aspect to be considered while designing structures. Lot of work has been reported by many researchers who worked to study the effect of structures with irregular plan. This paper presents effects of plan and shape configuration on irregular shaped structures. Buildings with irregular geometry respond differently against seismic action. Plan geometry is the parameter which decides its performance against different loading conditions. The effect of irregularity (plan) on structure have been carried out by using structural analysis software ETABS for three different types of soil considering the effect of soil structure interaction. There are several factors which affect the behaviour of building from which storey drift and lateral displacement play an important role in understanding the behaviour of structure. Results are expressed in form of graphs and bar charts. Based on these conclusions have been presented.