Much of the recent social science work in the energy field has been focused on changing the behaviour of individuals at home through values, attitudes, and information about climate change. However, people do more than live in houses; some people make their livelihood in them. This presentation considers the role of intermediaries (e.g., architects, engineers, builders, etc.) and their work in creating change from the "middle-out" rather than the top-down or bottom up. It focuses on the nature and distribution of expertise in low-carbon renovation using a "system of professions" lens. From this perspective, professional groups compete and develop interdependently, based in part upon their ability to perform (and defend) the tasks within their jurisdiction. Growth in knowledge—in this case, the causes and impacts of climate change— can create a “new” legitimate set of problems and therefore an opportunity for new professional group(s). Who can best deliver low-carbon improvements over the coming decades? How will they be educated? Will the tasks be taken up by members of existing groups, or by new entrants to the market? The presentation addresses these questions with evidence drawn from developments in the residential sector, mainly in the United Kingdom.