The term Big Data refers to large amounts of data coming from multiple resources, and to the techniques used to collect, manage and analyze them. In this paper, we focus of the collection of such data in complex physical environments like digital houses, smart buildings or connected plants. Precisely, we present a distributed, autonomic mediation framework named Cilia. This framework facilitates the design and deployment of mediation chains and their management at runtime. We also present a motivating example in the field of smart building and we explain why autonomic features are absolutely necessary in domains characterized by important environmental dynamism and by evolving needs of decisionmakers. Cilia is currently validated in collaborative projects with the Orange Labs.