Promoting energy-efficient retrofit of existing buildings to achieve carbon neutrality by 2050 is critically vital and challenging. The bulk of outdated educational buildings in particular are of grave concern since they are not only have a significant negative impact on the environment but also dangerous to inhabitants’health. This study laid the groundwork for understanding the connection between occupant health and energy efficiency. This study proposes a prioritized strategic GR framework in South Korea’s aging preschools. The possible prospects and levels of development in the GR plan are identified by this evaluation. Policy markers, educators, and other key stakeholders may help to create a more sustainable and healthy environment by putting the recommended framework into practice.