People leave their marks on the environment through the personalization of their spaces. In this regard, personalized space will allow people to make inferences regarding the occupant’s personal and social characteristics. This research attempts to study the issue of impression formation based on the cues that people leave behind in their primary spaces and how impressions are linked to the Stereotype Content Model. A total of 166 participants, young and mature students, took part in the research. All of them observed photographs of bedrooms, each one with a single owner; afterwards they completed a questionnaire considering the spaces’ potential residents. Results suggest that observers accurately identify residents’ sociodemographic variables. In addition, factor analysis shows that observers infer personality traits related to the two dimensions of Warmth and Competence. Finally, it is detected that young and retired observers perceive residents in a particular way, depending on age and gender criteria, respectively.