Smart Lighting Integration in Educational Buildings: A Climate-Responsive and User-Centred Framework for Classroom Retrofit

This study develops and applies a climate-based, user-centred and data-informed framework to assess lighting performance in educational buildings through the integrated use of daylight, high-efficiency LED systems and smart lighting controls. The research was conducted as a case study in university classrooms in Madrid, Spain, using a mixed-methods approach that combined in situ illuminance measurements, climate-based simulations with DIALux Evo 12.1, lighting energy assessment and structured user-perception surveys. The main objective was to quantify the dynamic interaction between daylight availability, electric lighting demand and perceived visual comfort, while assessing the energy-saving potential of daylight-responsive control strategies. Results show that the existing LED systems meet current illuminance requirements, with calculated lighting power density values ranging from 4.38 to 12.47 W/m2. However, the analysis also reveals that high daylight availability does not necessarily guarantee better lighting performance, since excessive or uneven daylight can generate spatial imbalance, glare risk, and reduced visual stability. Survey results confirmed a strong student preference for daylight and exterior views but also showed that visual task clarity and glare control remain essential for user-centred lighting design. Overall, the findings demonstrate that effective classroom lighting retrofits should move beyond LED replacement alone towards adaptive, daylight-driven and user-centred control strategies capable of reducing energy use while maintaining visual comfort in educational buildings under Mediterranean climatic conditions.