The purpose of this study was to explore the relationship between windows and interior design preferences in enclosed office spaces. The research sample consisted of forty executives from NASA. Subjects were asked to plan the interior design of an executive office space (simulated with a scale model) in response to four different window types and then asked to choose one of the four window types for the space. Subjects' reactions were observed and questioned throughout the experiment, to study the relation between windows and interior design preferences. Window functions and configurations, subjects' age, sex, country of origin, activity, and interaction levels were investigated as independent variables influencing the dependent variable perception of the relation between windows and interior design preferences. The data was analyzed by means of descriptive statistics and in-depth theoretical analysis of individual responses. Subjects' consciousness of the relation between windows and interior design preferences increased as activity and interaction levels increased. Window configurations and functions influenced interior· design preferences, especially furniture arrangement and color selection preferences. Interior design preferences influenced the choice of a window type to a considerable extent, perhaps as much as view and daylight. An overview of the study indicates that windows and interior design preferences are parts of a cyclic inter-relationship where each factor influences the other and therefore should each be considered with equal importance by both architects and interior designers. / Master of Science