The experience of a good indoor environment can result in positive perceptual outcomes, which is related to the occupant's well-being. Conversely, noise, uncomfortable temperatures and humidity, dim light, poor air quality, and pungent smells can compromise occupants' life quality, negatively affect their place experience, or even reduce personal health. In order to ensure positive indoor environments for occupants, a perceptual quality assessment has been introduced and extensively studied in recent years. Influenced by indoor environmental quality (IEQ), it is necessary and beneficial to explore how humans perceive and what effects indoor environments.

It is necessary for designers and researchers to address these issues associated with indoor environmental quality. Therefore, this Special Issue aims to gather articles that discuss indoor environmental quality and occupant comfort. The articles in this Special Issue encompass different research categories, ranging from conceptual analyses and reviews to research papers. These studies have investigated the characterization and perception of both individual indoor environments and complex environmental interactions, along with their management and design implications. The focuses of these investigations include both theoretical aspects (such as the relationships between environmental quality and psychological or physiological reactions) and methodological aspects (such as protocols and procedures of gathering objective and subjective data).