Abstract This study performed a three-dimensional numerical prediction for the induced airflow patterns and mean age of air (MAGE) around and inside a naturally ventilated school building, while accounting for the wind profile effect. Various fenestrations, hallways, and shading devices on the windward side of building were analyzed to determine how they affected wind velocity, the incident angle of airflow, and MAGE distribution inside classrooms. The numerical scheme is based on a commercial computational fluid dynamics (CFD) code, PHOENICS. The incline of incoming wind was observed on higher floors that decreased the air exchange rate in the simulated room. The inclined airflow could be effectively deflected downward through the breathing zone by hallways, 1.2-m shades as overhangs, and 0.6-m louvers. Based on this research, an appropriate combination of external attachments on the windward side of building façade can be utilized to enhance ventilation in school buildings. (See Appendix 1 for nomenclature.)