Humans’ curious nature combined with the evolution of technology, has led to the exploration of environments of extreme conditions, where survival is not possible without the use of technology.  Habitation of isolated and extreme environments is a challenge, that is both technical as well as psychological. In the present study, five habitats in terrestrial analogs, are analyzed in terms of their design, functions and external environment. These habitats are McMurdo Station of Antarctica, Hawaii Space Exploration Analog and Simulation, Mars Desert Research Station, NASA’s Extreme Environment Mission Operations facility and the International Space Station. Previous similar studies have shown that, the adaptation of humans in extreme environmental conditions, as well as isolation and confinement, is difficult and can lead to depression, boredom, seclusion from the group, social deprivation, sensory deprivation and other negative effects. Taking this into consideration, design factors are being studied in order to enhance the habitability of the habitat and the psychological well-being of the inhabitants. The main ways of achieving this goal, is the proper allocation of space, provided personal space for every crew member as well as proper usage of the common areas in order to enhance productivity and interaction among crewmembers.