The study course gives an overview of the stages and basic principles of creating a spatial environment, focusing on the interior design stage as the most detailed and the most directly related to the user. The theoretical part of the study course analyses the principles of functional differentiation of spatial environment, spatial perception and specifics of interior design, emphasizing the characteristic types of interiors and their spatial organization, as well as aspects related to environmental accessibility and universal design, equipment dimensions and material and form design. In the practical part, students elaborate specific interior development ideas, emphasizing the connection of architectural functional and ergonomic parameters with engineering and technological solutions, creating an expressive and unified vision of spatial environment development.