In the architectural field, energy reduction of new architectures for reducing emitting CO2 and energy consumption has been recommended since 2000s. By reflecting this, the supporting system and institution weighting on new buildings have been formed. However, based on 2014, with the era of existing buildings amounting to 6.8 million, the target for energy reduction has been changed from new buildings into existing buildings. Since the renovation plan or remodelling for energy reduction is executed in the existing buildings, which have been supplied more than new buildings. And also, the rate of CO2 emission came to be higher than the rate of CO2 for new buildings. Therefore, it is necessary to change the support system focusing on new buildings into the support system of existing buildings for activating green remodelling. In order to activate green remodelling, institutional support of government, technology development related to green remodelling, green remodelling manual development for building owner and residents are required to be established systematically. In this study, case analysis of technology and institution for activating green remodelling market in domestic and foreign country, plan to secure support system, applying the current situation, will be prepared. For the establishment of green remodelling support system, the activation of green remodelling market is predicted and the energy efficiency improvement and the emission of environmental load are expected.