Adaptation is very important in IOT systems, due to their continuously changing environments. Changes may come from different elements of the architecture underlying an IOT system. Existing literature pays special attention to changes in the Service layer using evolution agents or context aware approaches to manage adaptations to said changes. In this paper, we elaborate on eight challenges that developers face when building adaptive IOT systems. Such challenges take into account changes at the Services layer, but also in the Middleware and Physical layers. These challenges serve us as a research agenda to foster IOT technology. As a starting point, we design an architecture to deal with the posited challenges. Various of the architectural components are inspired on a reference architecture, and complemented by new components to manage dynamic adaptations in response to the identified challenges. Preliminary experiments provide an initial insight about the feasibility and/or impact of our adaptive architecture.