Zoomable User Interfaces (ZUI) can help people perceive and interact with large collections of information. These large collections complicate the task of creating ZUIs. In this paper the ORRIL (Objects, Regions, Relations and Interface Logic) framework is defined and presented as a technique for aiding ZUI design and creation. ORRIL makes explicit the data that appears in a zoomable information space, while simultaneously emphasising the relationships between user actions and transforms of the data. This is important for modeling and clarifying the processes that occur within a ZUI application. From the perspective of an implementer it may be used as an underlying model when designing and implementing a framework for building ZUIs.