Influence of variations in CO2 emission data upon environmental impact of building construction

To reduce CO2 emissions from the manufacturing phase of building materials, sustainable structural design has been introduced. However, embodied CO2 emission data in construction materials vary significantly depending on life cycle assessment (LCA) techniques, nations, and the time of data formation. In the embodied CO2 emission data used in recent literature, the percentage differences in CO2 emission data for concrete and steel as two typical building materials found to be 267 and 863%, respectively. These variations cause significantly different results in sustainable structural design. Thus, to avoid the dependency on the selection of embodied CO2 emission data, a sustainable design model with a new design variable of CS-factor is proposed. It is found that CS-factor ranged from 0.0208 to 0.4545 for current embodied CO2 emission data. It is revealed that the environmental impact for construction of the same beam structure can be increased by more than 9.65 times (from 191.7 to 1851.1) due to the variation in CO2 emission data. Also, the total construction cost for the same beam can be increased by 152.4% due to the variation. For the future of the construction industry, it should be noted that building construction based on available embodied CO2 emission data may not be a solution for green construction.