This study evaluates and compares the environmental impact of timber, concrete, and steel as building materials.This study designed a target member (beam) with equivalent structural performance under the same design conditions, such as span and live load, and compared the environmental impact. The carbon footprint analysis was conducted using Life Cycle Assessment (LCA) methodology, with a functional unit of 1-meter length of the designed beam and a cradle-to-gate system boundary. The study found that timber has a lower carbon footprint than steel and concrete, with the lowest carbon emissions during the product stage. Notably, the study also found a significant difference between the two environmental impact comparison methods, unit volume-based and structural performance-based.The findings demonstrate the sustainability of timber in high-rise construction and its potential to contribute to carbon neutrality while offering exceptional engineering capabilities. Further research is needed to improve the structural assumptions and LCA to evaluate the environmental impact of building materials more accurately.