This document summarizes a study on the effect of infill wall stiffness variations on the behavior of reinforced concrete buildings under seismic demands. The study models a 5-story reinforced concrete building located in seismic zone III of Nasik City, India, with and without considering the stiffness of infill walls. Static analysis using the equivalent lateral force method and dynamic analysis using the response spectrum method are performed and results such as base shear, fundamental time period, and story shear are compared. The goal is to better understand how accounting for the stiffness of infill walls affects the performance of reinforced concrete buildings during earthquakes.