A study conducted by Nässén et al. (2012) compared the net current costs, total material, carbon, and energy costs of two alternative buildings: timber and reinforced concrete. The study did not consider labor, construction, maintenance, and demolition costs. The data obtained indicated that the material cost difference between the two buildings was small. Therefore, the study noted that the cost-effectiveness of timber buildings is uncertain. In Kim et al.’s study (2013), two structural frames, reinforced concrete and steel, were compared in terms of environmental performance and construction costs, in the direction of the LCA and LCC systems. The study focused particularly on the construction phase. The findings showed that reinforced concrete structural frames had 26% less CO2 emissions and 29% less energy consumption than steel structural frames. It has been stated that a large portion of the emissions are caused by the steel production process. The study also showed that the reinforced concrete framed building’s total cost was approximately 9.8% lower than the steel framed building. Balasbaneh & Ramli (2020) provide a comparative life cycle assessment of steel and concrete prefabricated buildings in Malaysia. The structures were assessed according to five environmental impact categories using SimaPro 8 software. These impact categories are non-renewable energy, greenhouse gas emissions, respiratory inorganics, mineral/raw material extraction, and land use. The findings show that the emissions of steel structures are higher than concrete structures only in the greenhouse gas category, while the emissions of concrete structures are higher in other environmental categories. The study also analyzes these two types of structures in terms of life cycle cost effectiveness. Although the construction phase cost of the steel prefabricated structure is higher, the overall life cycle cost of the concrete prefabricated structure is higher. The number of integrated studies in the field of LCA and LCC is increasing significantly in the literature. However, studies including comprehensive evaluation approaches are limited. Therefore, the development of comprehensive methodological approaches has great importance. The study aims to make a comparison of different structural systems in terms of environmental impact and economic costs, and to support the decision-making process in the early design phase. A system framework for evaluating alternative structural systems is explained. This LCA and LCC integration approach provides a framework for considering all environmental (LCA) and economic (LCC) impacts in decision-making processes. It aims to analyze and evaluate alternative structural systems, focusing on environmental impacts and costs.