Demographic changes have a profound impact on residential energy consumption. The number of single-person households is rapidly increasing around the world and the percentages of elderly individuals in the populations of almost all countries are expanding. The objective of our research was to analyze how single-person households and elderly households impact residential energy intensity, defined as annual residential energy consumption per capita per unit of finished area of the household’s house, and how those impacts interact with each other using South Korea as a case study. Our findings suggest that the rise of solo living and an ageing population have overlapping effects on energy consumption and threaten future improvements in residential energy intensity. Specifically, an increase of single-person households results in a decline in energy intensity regardless of whether the household is elderly or non-elderly and the effect of an increase in elderly households on energy intensity depends on whether the household is single- or multiple-person. Given the similar average size of finished area for single-person households, the difference in per unit energy consumption between elderly versus non-elderly households likely comes from behavioral differences such as a greater use of energy-intensive appliances by non-elderly households than elderly households. However, for multiple-person households, the effect of such behavioral differences seems to be dominated by the effect of a house’s shared amenities. The common space and energy-consuming amenities of a house are shared by more individuals in non-elderly households, leading to more intensive energy consumption by non-elderly multiple-person households than by elderly multiple-person households.

人口变化对住宅能源消耗产生深远影响。在世界范围内，单身家庭的数量正在迅速增加，几乎所有国家的人口中老年人的比例都在增加。我们研究的目的是分析单身家庭和老年家庭如何影响住宅能源强度，定义为每户房屋完成面积的人均年住宅能源消耗，以及这些影响如何利用韩国相互影响作为案例研究。我们的研究结果表明，单身生活的增长和人口老龄化对能源消耗有重叠的影响，并威胁到未来住宅能源强度的改善。具体来说，单身家庭的增加导致能源强度下降，而不管该家庭是老年人还是非老年人，而老年家庭增加对能源强度的影响取决于该家庭是单人还是多人。鉴于单人家庭的完成面积平均大小相似，老年人和非老年人家庭在单位能耗上的差异可能来自行为差异，例如非老年人家庭比老年人更多地使用高能耗设备家庭。但是，对于多人家庭，这种行为差异的影响似乎由房屋共享设施的影响所支配。