## 5 Conclusions  
This study explored the interplay between the IEQ, energy consumption, and environmental impacts in an educational building over an academic year. Its findings reveal a complex interrelationship between these factors, highlighting seasonal variations in the IEQ parameters and energy consumption. While the building generally met the thermal comfort standards during the heating season (Category 1 for 33.3% and Category 3 for another 33.3%), significant challenges emerged in summer due to high temperatures and insufficient cooling. The lack of a mechanical ventilation system resulted in the CO\({}_{2}\) concentrations frequently exceeding the recommended levels, with values up to 1372 ppm. The noise levels consistently exceeded the acceptable limits, with a mean value of 51 dB. The lighting levels also fell short of the recommended standards, under 500 lx, due to the occupants' use of window blinds to block direct sunlight.  
The building's energy use intensity was 90.19 kWh/m\({}^{2}\)/year, and its energy performance index was 75.16 kWh/m\({}^{2}\)/year, falling within the average range for similar facilities in Europe but being significantly lower than its US counterparts. The life cycle assessment revealed a global warming potential of 120,199.82 kg CO\({}_{2}\)e/year, with natural gas consumption contributing 61.72% of this total. This underscores the need for integrated intelligent control systems, balanced approaches to optimizing IEQ and energy efficiency, and approaches to lowering the building's overall carbon footprint.  
Addressing the identified performance gap requires a more comprehensive, integrated approach. Implementing smart technologies within Building Management Systems to optimize the responsiveness to the actual building use and occupancy patterns is essential to enhancing energy efficiency while maintaining an acceptable IEQ. Furthermore, strategies for reducing the reliance on natural gas for heating (such as adopting renewable energy sources), improving natural ventilation, and optimizing lighting should be considered. These improvements could simultaneously reduce the energy consumption and environmental impacts and contribute to a more productive, comfortable, and healthy learning environment for its occupants.  
This research underscores the importance of holistic sustainability strategies for educational facilities, integrating IEQ, energy efficiency, and environmental considerations for the optimal outcomes.  
Conceptualization: T.R., R.-P.M. and A.-M.M. Methodology: T.R., R.-P.M. and A.-M.M. Software: T.R. and R.-P.M. Validation: M.I.P. and A.-M.M. Formal analysis: T.R. Investigation: R.-P.M. Resources: M.I.P. Data curation: A.-M.M. Writing--original draft preparation: T.R., R.-P.M., M.I.P. and A.-M.M. Writing--review and editing: T.R., R.-P.M., M.I.P. and A.-M.M. Visualization: T.R., R.-P.M., M.I.P. and A.-M.M. Supervision: T.R. Project administration: T.R. Funding acquisition: T.R. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Technical University of Cluj-Napoca through the GNaC ARUT 2023 program, grant number 22/01.07.2024, of the project \"Cladiri pOzitiv eNergetic in EduCaTie-CONECT\".  
Not applicable.  
The data presented in this study are available on request from the corresponding author.