This article draws on a co-design workshop with professionals working in the field of smart energy in the UK, to explore their imaginaries of smart homes and how these are (in)formed by their everyday ‘lay’ experiences. Smart home technologies (SHTs) are fundamentally embedded in future visions of energy transitions as they are expected to support actions to tackle climate change. Nevertheless, literature and adoption rates reveal an apparent gap between householders’ needs, expectations, and uses of SHTs, and how professional designers and developers view the same technology. Previous studies on SHTs imaginaries coming from industry and experts have focused on how users are represented in institutional visions, however, they routinely neglect the individual subjectivities of professionals producing such representations. The article presents three core results on the role of SHTs in digital energy futures: (1) it generates visual and textual conceptualizations of professionals’ imaginaries around smart domestic environments; (2) it identifies empirical insights on the formative role of professionals’ personal imaginaries for smart energy transitions; and (3) it calls for an alternative and more reflexive co-design practice to envision a fairer and more inclusive energy future.