Reinforced concrete walls are very efficient structural elements in terms of carryingthe lateral loads that are expected to affect the structures during the service of thebuildings. These elements, which are not used for economic reasons in buildings designedin areas with low seismic hazard, can actually provide a significant increase inperformance with a very small increase in construction cost. In this study, a total of9 building models have been created and the relationship between optimum reinforcedconcrete wall ratio and cost on these buildings has been investigated. The designand analysis of the models were carried out according to the criteria specified inTSC 2018. Three different structural systems specified in TSC 2018 were used in thedesigned models. These structural systems used; RC frame structures, RC wall-framestructures and RC wall structures. These structures were analyzed by Response SpectrumMethod which is linear analysis method and base shear forces were obtained.Then, push-over analysis, which is a nonlinear analysis method, was applied to obtainthe base shear forces that the structure can actually carry. After the analysis, thequantities of materials to be used for the construction of the structural systems of themodels were calculated and current manufacturing prices and rough costs were calculated.In order to compare the obtained costs with the structural performances,nonlinear shear forces and linear shear forces ratios were calculated and the overstrength factors were calculated for each model. In the light of the data obtained fromthe studies in the literature, when the over strength factors and cost values are examinedtogether, it is concluded that the optimum design for the conditions specifiedin TSC 2018 will be provided with the RC wall ratio between 0.001 - 0.0016. It is concludedthat lateral load carrying capacity of construction increases up to 650% byincreasing the construction cost by 17% for the designed models.