Seismic-induced damages in reinforced-concrete (RC) buildings were primarily associated with materials’ low strength and poor properties. This study aims to investigate the seismic response of RC structures according to the different material’s strength and design spectra. Adaptive static pushover and eigenvalue analysis were performed for four different design spectra, five types of concrete, and two reinforcement grades. Four different design spectra were obtained by considering discrete geographical locations with different earthquake risks via the updated Turkish Earthquake Hazard Map 2018. Structural analysis was carried out for a sample RC building using these spectrum curves and material strengths. It has been observed that the structure becomes more rigid as the strength of concrete increases. This situation manifested itself with an increase in period values and a decrease in the stiffness values. Stiffness values of the building are independent of reinforcement. As the concrete strength decreases, the structure’s seismic capacity decreases while the displacement’s demand for predicted performance levels increases. Moreover, an increase in the tensile strength of reinforcements substantially increases the seismic capacity of the building. The study also determines that the site-specific design spectra obtained for different provinces are used in the analysis affects the demand displacements values considerably. The material differentiation between the stories in the building was also examined in this study. It can be a source in terms of how material discontinuity affects building performance.