In Korea, buildings are becoming skyscrapers due to restrictions on land. The performance-oriented design was introduced in 2009 for fire safety of such buildings, but the application of the combustible data through engineering design and experiment is a poor reality. Large buildings are used for complex purposes, especially since the density of the office facilities is high, the study conducted a study on the combustible materials of the office facilities and the thermal speed and fire load of the main combustibles of the office facilities were calculated.