This research aims to understand the factors that contribute to the quality of life within isolated, confined, extreme (ICE) environments by investigating the architectural elements that affect an individual’s spatial perception, their manifestation in ICE environments, and how spatial confinement and isolation contribute to changes in an individual’s perception of spaciousness. The researchers performed an in-depth examination on three different habitats, designed to simulate life in ICE environments, to identify which architectural elements were important contributors to positive and negative changes in spaciousness. For further explorations, fourteen design professionals were asked to evaluate these habitats using the Spaciousness and Crampedness Scale (SCS) and measuring the relative estimation in error of habitats’ areas. Afterward, the evaluations were compared with the examinations. The results indicate that the environment’s geometry, lighting, color, and texture significantly contribute to perceived spaciousness when evaluated through qualitative and quantitative methods.