The aim of any engineering design is to minimize the total cost of the structure without compromising the functional requirements. In this way, the utility of the structure to the users in particular and to the society in general, will be maximized. Life-cycle cost analysis is recognized as the only suitable tool for assessing the structural performance in order to determine the best investment option and achieve the optimal techno-economic status of a structure when the structure is expected to be functional for a long period of time. In order to create an environmentally-conscious building, the environmental impacts of the entire service life must be known. In the current study, life cycle assessment for construction and operating stages of a two-dimensional reinforced concrete frame of an office building under seismic hazards has been carried out. Incremental dynamic analysis (IDA) is a method that can be used to satisfy the seismic capacity of a structure under different possible earthquake stimulation intensities, so this method is included in the life-cycle cost analysis. In this thesis, life-cycle cost considering the probabilities related to different hazard levels has been examined in terms of components' cost, environmental cost and social cost. Moreover, an optimized mode with regard to design criteria has been drawn with respect to the pattern obtained from the analysis of fifteen frames under 14 earthquake records with the help of incremental dynamic analysis. The most important environmental costs of this study include the cost of air pollutants, the potential of global warming, fossil fuel depletion, water intake and human health. Environmental effects are also assessed by assigning a score. At the end of the research, various optimization goals are defined. In order to perform optimization measures, first, the various functions of the interstory drift, the floor maximum acceleration, and loss cost were directly or indirectly extracted according to the consumable materials, then according to the design constraints proposed in the allowed range, the optimization has been done. This research shows the importance of considering the environmental aspects of a structure. The results indicate the significant contribution of social and environmental aspects in the life cycle costs. Results also show a reduction in the life-cycle cost of some scenarios, including B3, B5, A5, and A8, despite increasing initial costs. According to the results, the environmental cost of weak and strong structures contributes about 19.70% and 21.44% of the initial costs respectively. On average, 20.32% of the initial costs are environmental costs. Also, in the loss costs section, environmental costs contribute from about 10.26% in weak structures to about 12.48% in strong structures.