The software-driven assistance of elderly and impaired people in their every day life requires the integration of heterogeneous devices and assistive services. The lack of interoperability hampers the integration and usage of these devices and services. Furthermore, one objective in the field of Ambient Intelligence and Human Machine Interaction is the adaption of assistive services to the user(5). This is deeply rooted in the idea that the usage of ambient technologies still means a barrier for elderly and impaired people and prevents them to trust and use these technologies. But as these technologies aim at supporting and not restricting elderly and impaired people, a methodology is needed to overcome the barrier of using ambient assistive technologies. In this paper, we present an approach to a) enable a simplified integration of heterogeneous devices and services by the Web of Things recommendation and b) a lightweight AAL ontology together with a rule-based engine called Sherlock in order to demonstrate the advantages in representing and linking user intentions to device capabilities using Semantic Web technologies. Moreover, we show how this semantic representation in the context-aware Sherlock engine is used to derive user intentions by recognising device events. The practical applicability of the presented approach is demonstrated in a real-world use case from the AICASys project(1). (C) 2016 The Authors. Published by Elsevier B.V.