Add to ORKGAbstract—A smart space is a physical space with heterogeneous smart objects that collaborate and share information to perform tasks desired by users. Interoperability among smart objects is the key challenge in smart spaces. In this paper, we discuss a semantic interoperability approach for smart spaces introduced by the SOFIA (Smart Objects for Intelligent Applications) project. A semantic interoperability architecture is introduced and implemented for a use case scenario deployment. This deployment consists of many heterogeneous smart objects, designed and manufactured by different companies and institutions, that exchange information through the interoperability architecture. The architecture, realized as a smart home pilot, is evaluated...