In this paper, we present scenarchitectures, a means of raising the level of design of advanced interactive systems. Scenarchitectures combine elements of scenarios and system architectures, and can be used during the user interface design process as an adjunct to other design tools such as textual scenarios and story boards. Meanwhile, scenarchitectures can be automatically transformed to system architectures, providing a link between design and implementation. Using two existing scenarchitectural notations, we investigate the role of scenarchitectures in the design process. We then show how model-transformation techniques can be used to automatically derive system architectures from scenarchitectures, and conclude with concrete examples of the application of the scenarchitectural approach to the design of a mixed-reality system.