Recent studies have shown that architectural interior forms could impact the affective state of inhabitants. However, the direct relation of specific forms with specific affective states is difficult to determine. In addition, no systematic categorization of architectural forms and their relation to emotional states exists. The investigation of the impact of architectural features on inhabitants' emotions is further complicated by the use of two-dimensional images of forms in laboratory investigations, which cannot perceive real-world architecture. Furthermore, the interior form consists of a combination of different forms rather than only pure forms, which was considered in previous studies. This study aimed to fill these gaps by evaluating interior forms on the basis of clustering different images of built living rooms throughout history as well as their impact on emotions. This study used pleasure, arousal, and dominance ratings with an emphasis on individual differences in personality. Virtual sample rooms were created based on formal clusters of architectural forms. Results showed a relationship between forms and emotional states for different personality traits. This work provided a novel approach on the influence of architecture on emotion by considering systematic form categorization and combinations, personality differences, and a virtual reality setup.