## 1 Introduction  
The impact of energy consumption on the built environment is a growing concern in sustainability, posing challenges at the intersection of environmental, urban planning, and social issues [1, 2]. Buildings are significant contributors to greenhouse gas emissions and energy consumption, directly influencing climate change and energy poverty [3]. Reducing energy consumption and adapting buildings to future climatic conditions has become a global priority for architects and engineers, who aim to balance energy efficiency with occupant comfort [4, 5]. Public buildings, particularly schools, play a crucial role due to their educational and social functions and their potential to generate long-term economic and environmental benefits [6, 7]. In Europe, educational buildings represent approximately 18% of non-residential structures, with the majority built before 1990, an era when climate and energy efficiency were not prioritized [8; 9]. Aging infrastructure in combination with rising temperatures, especially in southern Europe, have resulted in inadequate indoor conditions during extreme heat events [10; 11]. This makes it essential to retrofit schools to address current and future climate challenges, as Mediterranean regions face increasing thermal extremes that could endanger occupant health and well-being without appropriate adaptations [12; 13]. Retrofitting educational buildings presents an opportunity to improve efficiency and comfort through passive design strategies that utilize local climatic resources. Passive measures--such as solar orientation [14], natural ventilation [15], and thermal insulation [16]--are particularly effective in Mediterranean climates, where seasonal variations require tailored solutions [17; 18]. These strategies offer sustainable low-cost alternatives to mechanical systems, reducing the reliance on energy-intensive methods while improving indoor comfort [19; 20]. Incorporating passive measures into retrofitting ensures long-term value by lowering emissions and strengthening the climate resilience of educational facilities. In this context, the European Union has established legislative frameworks and targets to reduce energy consumption in public buildings. Strategies such as the European Green Deal and Directive (EU) 2018/844 aim to transform buildings into nearly-zero-energy buildings (nZEB) by 2050 [21], promoting architectural interventions that incorporate both active and passive improvements into building systems. However, most initiatives to date have prioritized upgrading thermal systems, often overlooking the potential of passive strategies for optimizing comfort and energy efficiency [22; 23]. Since passive design is a fundamental tool for achieving sustainable retrofitting, it is critical to integrate passive strategies that are customized to specific climatic and regional conditions. The main aim is to assess the effectiveness of passive retrofitting strategies in improving energy efficiency and thermal comfort in educational buildings under climate change scenarios. To achieve this, the study focuses on a representative pilot case: the Santa Rosalia Preschool Center in Granada, which serves both educational and residential purposes for on-site maintenance staff. The research evaluates the energy performance of different retrofit measures applied to this building across three time periods (2024, 2050, and 2080) under the Shared Socioeconomic Pathway (SSP) climate scenarios. These scenarios represent the most recent framework of climate scenarios, although their implications for building energy performance have remained unexplored. In this regard, most scientific literature has traditionally relied on the Special Report on Emissions Scenarios (SRES) [24] and Representative Concentration Pathways (RCPs). This approach thoroughly evaluates the current effectiveness of the proposed solutions and projects their long-term benefits and limitations in response to expected climatic variations throughout the 21 st century.