Turkey is considered a very seismic country, with 95 percent of the population living in a seismic-prone area, and earthquakes seriously threaten them. Structural integrity and public safety require earthquake-resistant construction. This study considers the seismic performance of a five-story reinforced concrete (RC) building with five different square column sections. After conducting a finite element analysis to determine the structural response to earthquake loading with and without shear walls under the Turkish Earthquake Regulations (2018), Recently, the added reinforced concrete shear walls (RCCSW) were equally spread over the project, contributing to 0.2% of the total project area and significantly improving structural performance. Results suggest that shear walls may be integrated to increase buildings with 35×35 cm and 55×55 cm concrete columns at about 69.4% and 90.6%, respectively. Additionally, seismic floor displacement was reduced nine times compared to the reference model. These results emphasize the crucial function of the column dimensions and shear walls in preventing seismic damage, suggesting the need for the optimal structural design of the earthquake regions.