Building and running AmI applications suffers from inflexible and/or difficult to achieve interoperability of basic technological elements. Semantic technologies represent a promising approach how to enable a flexible architectures providing wide range of interoperability (e.g. service-service, service-device, service-goal, etc.). The focus of the presented paper is on incorporating these technologies into the model driven architecture approach to designing and running AmI applications. Employment of semantics is illustrated for design-time as well as run-time. Transition from physical to semantic devices enables developers to work on a higher level when designing applications. Enabling semantics in run-time provides possibility for flexible discovering and resolving.