Ambient Intelligence (AmI) promises future environments that support the well-being of their inhabitants through comfort and assistive environments. For the elderly users, Ambient Assisted Living (AAL) scenarios are targeting safe and independent living at home. Especially the integration of home automation components, such as intelligent light, window, and climate controls seem promising for such scenarios. In this paper, we present a new development method that is based on a detailed three-dimensional model and show how the model can be used for designing and evaluating assistive environments. Such a system has been developed and deployed. We present an architectural foundation of how Universal Remote Console technology can be applied to synchronize the virtual environment model with the real world. Furthermore, we extend previous work on Dual Reality by introducing the concept of Synchronized Realities that includes the synchronization between remote AmI environments. We will discuss application scenarios and show two demonstrators that we have implemented based on the proposed development method.