Abstract
Energy consumption and carbon dioxide emission due to retrofit or reconstruction of an existing office building were analyzed by using basic sector classification Input/output table and the construction data of the actual projects. With the retrofit case, energy consumption per unit floor area is 3.8 GJ/m^2 and carbon dioxide emission per unit floor area is 306 kg - CO_2/m^2. With the reconstruction case, if the quality of the finish work is equivalent to the retrofit case, enerery consumption is 11.2 GJ/m^2 and carbon dioxide emission is 966 kg - C0_2/m^2 due to the effect of demolition and reconstruction of the structure.
