This paper proposes a physical toolkit and a flexible software framework to simplify the design and exploration of interactive systems for multiple users, devices, and applications in a smart environment. The toolkit, called Elastic-Room, was designed as an infrastructure for interaction design, in which each device is a component that works collaboratively in the smart environment. The supporting software framework includes a dynamically reconfigurable intermediary which simplify the mapping of each device and also use simple protocol to broadcast information to each device. Finally, we demonstrate the Elastic-Room architecture by providing some implemented examples, which are organized in a prototype space of ubiquitous computing full of interactive components.