Due to climate change and the increase in energy costs, the number of people with heat-related illnesses is increasing among older adults. Although the government implements adequate thermal environment supporting programs, they mainly support energy costs based on income levels during winter. The purpose of this study is to compare the home energy costs, energy cost burden, energy cost burden stress level, and home thermal environment and home performance satisfaction of low-income older adults living in old houses in summer and winter. The target population of this study was senior households living in old single-family and low-rise multifamily houses located in Jingu, Busan, and a total of 50 older adults participated in the face-to-face survey. While the result of this study showed that winter home heating conditions are worse than summer, the participants lived in inadequate indoor temperatures even in the summer. It is necessary to consider expanding energy-supporting programs based on the actual condition of low-income seniors who do not currently receive home energy support policies and the thermal environment of their homes. For low-income seniors living in older homes, there is a need to not only support energy costs, but also improve home building performance over the long term. In addition, it is necessary to expand energy support policies that are concentrated in winter to summer and to support low-income seniors living in old houses who are in the gap of energy support programs. This study is expected to be referred to as a basis for future policy improvements.