In households, residents should understand the actual conditions of energy usage in order to increase the effectiveness of energy-saving actions. Accordingly, the "Low-Carbon Home Consulting System" was developed in this research. First, the energy consumption and lifestyle of residents were identified through a questionnaire survey. Then, the system was developed based on the survey results. Energy consumption broken down by usage was estimated with this system. Finally, the energy savings were estimated. In this way, the CO2 emissions of individual households were reduced by up to approximately 40% relative to the emissions prior to applying the developed system. This study demonstrates that, by facilitating effective energy-saving actions, energy consumption and CO2 emissions can be reduced while maintaining a healthy environment for residents.