Ventilation shafts can aid natural ventilation in buildings. Natural ventilation provides ventilation for occupants that can provide thermal comfort conditions. This study attempts to increase air flow rates, which can provide thermal comfort conditions, in occupant spaces of a low rise commercial building by using a ventilation shaft. While doing so the time period of effective natural ventilation also increases. This is achieved by optimizing the occupant zone and ventilation shaft design to maximize the air flow inside them. This design optimization is achieved by identifying the range of influence building and ventilation shaft components of height and openings have on both types of buoyancy and wind driven air flow. ? A comparison of air flow rate and thermal comfort conditions achieved by the airflow on different models having different ventilation shaft designs are performed to verify the potential of a ventilation shaft in increasing effectiveness of naturally induced airflow. Multi zone airflow and contaminant Transport analysis (CONTAM) software by National Institute of Standards and Technology (NIST) is used to perform all the calculations.