This study describes the environmental impact of the material production, transportation, and construction phases from the construction site perspective. CO 2 emissions for each process were determined using the Korea Life Cycle Inventory Database (LCI DB) in the material production phase, and the actual amounts of oil consumption for transportation equipment were identified in the material transportation phase. Generally, the oil and electric energy consumed during the construction was evaluated by direct monitoring. Through the construction period and cost according to work type, a correlation with CO 2 emissions was also investigated. In addition, CO 2 emissions were examined through the system capacity and gross floor area for each work type. The calculations have shown that CO 2 emissions from the material production phase constitute 93.4% of the total CO 2 emissions. In addition, CO 2 emissions from the material transportation and on-site construction account for 2.4% and 4.2% of the total CO 2 emissions, respectively. This paper concludes that it is important to select appropriate input materials and resources for the reduction of CO 2 emissions. Furthermore, the amount of CO 2 emissions arising from the construction site was reduced by finding and practicing measures to reduce CO 2 emissions for each process.