This paper aims to reveal the detailed household operational energy consumption patterns in major cities of Indonesia. A total of 297 households were surveyed in Jakarta, while 247 households were investigated in Bandung, focusing especially on unplanned landed houses. The detailed information about household appliances and gas consumption were investigated through face-to-face interviews. The households in the two cities were grouped into three clusters based on their ‘wealth’and ‘household size’. It was seen that the average household energy consumption and their CO2 emissions increase with the increase in the above two factors, in particular the ‘wealth’. The household energy consumption in major Indonesian cities was predicted to increase very sharply in line with the rise of middle class in the near future if proper energy-saving strategies are not implemented. We recommended the following potential energy-saving strategies for urban houses in Indonesia:(a) provision of more apartments rather than landed houses (from the viewpoint of energy),(b) natural lighting and use of LED lamps,(c) passive cooling techniques wherever possible, and (d) insulation for building envelope.