The paper provides a state-of-the-art review of fuel cells operating in the domestic built environment. Fuel cells produce heat when generating electricity, thus they are of particular interest for combined heat and power (CHP) applications. As this paper’s focus is the domestic built environment, only micro-CHP applications are considered. The review commences with an examination of micro-CHP in the built environment and then appraises domestic fuel cell technology. It concludes with an assessment of the present development of, and future challenges for, domestic fuel cells; specifically the operational advantages they offer compared to conventional micro-CHP technologies. As fuel cells are an emergent technology the paper draws on a breadth of literature, data and experience, mostly from the UK, Japan, USA and Australia.