The Greek state has set forth the goal of transforming educational buildings into “zero carbon footprint buildings” and school units into “sustainable schools”. This endeavour constituted the rationale for the present study, which aimed to enhance knowledge in the areas of energy conservation and environmental education for sustainable development. Using parametric and statistical analysis techniques, the study analyses the energy status of educational buildings in relation to radical renovations and participation in funding programs. Additionally, it estimates the percentage of energy and cost savings after energy interventions, while also evaluating the adoption of environmentally friendly behavior by educational communities. The results indicate that Greece has initiated the transition towards climate neutrality, but further reinforcement through policy and economic measures is necessary. The energy-saving potential in educational buildings and the pro-environmental behavior of educational communities are crucial factors for sustainable development and the transition to decarbonisation by 2050.