## 4 Results and Discussion
In the current scenario, the quartile values of the hourly heating demand were reduced by 0.91 kWh for Q1, 11.18 kWh for Q2, and 25.18 kWh for Q3. These reductions translate to an average increase in savings of 23.59% in heating demand compared with Case 1. For cooling, the savings remained similar, with a slight increase of 0.67%. Figure 4: Total energy demand achieved in Case 1 (window replacement). Therefore, adding insulation effectively reduces the heating demand but has limited effectiveness for cooling. The analysis extends to the SSP scenarios, which project an increase in cooling demand but only slight improvements in savings compared with Case 1. Annual percentage savings for cooling increased by 1% compared with Case 1. Although the strategy's effectiveness for cooling demand remains limited, it achieves notable heating demand reductions of up to 83%. In Case 3, the combination of window replacement, facade insulation, and roof insulation was analyzed. This is the most comprehensive envelope improvement framework proposed in the study. Figures 7 and 8 present the obtained results. Adding roof insulation does not change the trends observed in the previous cases. However, the energy savings achieved with this improvement are more pronounced: an annual savings of 9% for cooling and 74% for heating in the current scenario. In future scenarios, heating savings could increase to 90%, effectively eliminating heating energy consumption. For cooling, future savings could increase by up to 1% compared with the previous cases. Figure 5: Scatter plot of the hourly heating and cooling energy demand achieved in Case 2 (window replacement and facade insulation). Figure 6: Total energy demand achieved in Case 2 (window replacement and facade insulation). Figure 7: Scatter plot of the hourly heating and cooling energy demand achieved in Case 3 (window replacement, facade insulation, and roof insulation). This highlights the duality of the strategy: it is highly effective for heating but offers limited savings for cooling. Given the future trend under the scenarios--an increase in cooling demand and a decrease in heating demand--energy retrofit strategies must go beyond envelope improvements. Incorporating high-efficiency HVAC systems, self-consumption, and renewable energy sources (e.g., geothermal energy) might be critical. However, current budget constraints may limit the implementation of these measures in educational buildings. A significant observation is the progressive decrease in the coefficient of determination between the hourly energy demand values of the current case and the improved case across the different retrofit measures. For heating, Case 1 values ranged from 88.4% to 97.4% for heating. In Case 2, they dropped to 78.1% to 93.1%. In Case 3, they declined further to 64.3% to 87.7%. This progressive reduction reflects a weaker association between current and improved values as the envelope retrofit becomes more comprehensive, primarily due to a higher concentration of instances with zero energy demand. This trend is not observed in the cooling demand, where the energy consumption remains high. Coefficients of determination range from 95.7% to 98.8% across all analyzed combinations. These findings suggest that the energy performance of educational buildings cannot be fully optimized through envelope retrofitting strategies alone. While widely implemented in the Spanish built environment [41], these measures may have limited effectiveness in warm climate zones. Additionally, the results highlight the amplified impact of climate change under SSP scenarios compared with prior studies. Earlier research suggested that SKES or RCP scenarios could increase energy demand by 34% to 44% by 2050 for educational buildings [54]. However, this study shows that projected increases may be significantly higher under the new SSP framework. Specifically, for buildings with mixed uses, increases of up to 83% were observed.