Passive spaces are a passive design strategy that aims to reduce energy consumption and increase user satisfaction in buildings. One example of passive space is the air shaft. The air shaft is a vertical void within the building from the ground level to the roof level, and it provides the building with natural ventilation and daylight, especially in deep-plan buildings. However, the function of the air shaft is questioned due to its impacts on residents' needs. This study assesses the effects of air shaft specifications on residents' satisfaction with the indoor environment quality of air shafts and adjoining spaces. Survey questionnaires were distributed to residents of apartment buildings. The results proved that air shafts have a significant negative impact on residents' satisfaction. The findings of cross-tabulation analysis illustrate a significant relationship between the air shafts' specifications and the residents' answers. The analysis also showed that the air shafts that are closed from the bottom and include A\C outdoor units have a more negative impact on the thermal environment and air quality. Regarding the air shaft areas, the small areas have a high negative response regarding bad smell, the view, visual and acoustic privacy, and thermal environment. From the indoor environment quality perspective, this study emphasizes the need to consider the impact of air shaft design on a building's performance and residents' satisfaction. The results of this study are expected to contribute to the development of future passive spaces design.