Abstract: People often behave in Smart Environments by relying on spatial metaphors that deserve to turn into architectural abstractions. The paper presents a set of space-aware communication primitives that support the seamless integration of application components in an open-ended Smart Environment. Environment spaces provide subjective views of the environment according to specific spatial models, be they physical or logical. Software components communicate in a publish/subscribe style by contextualizing information in the spaces they are aware of. Space mappings allow components to interact even if they rely on different spatial models. The paper introduces a formal definition of basic spatial models and describes the spaces-based architectural abstractions through a reference example. Then it presents SIS (Space Integration Services), a concrete framework that reifies the abstractions, together with some performance measurements. Finally, it shows a concrete implementation of the reference scenario and compares the proposed approach with related work.