The present paper starts with a crucial discussion about the imbalance between technological and human concerns in the context of human-computer interaction, an imbalance that has arisen partly from the mechanistic aspect and its impact on interaction design. We then introduce the concept of Blended Reality Space, interactive mixed reality environments where the physical and the virtual are seamlessly combined and affect each other. The conceptual grounding and practical examples that illustrate our approach to interaction design are then discussed, adopting a standard figurative representation of blends. This helps understanding the role of blending that meaningfully bridges unbalanced separations between cognition and action, and the physical and the virtual. As a concrete example, the AGNES project, which is aimed at developing “user sensitive home-based systems for successful ageing in a networked society”, is introduced. We believe that the emphasis on ‘balance’ or appropriate blending is very important in the development of better interactive systems for health, capitalizing on seamless combinations of the virtual and the physical in Blended Reality Space.