Professionals involved in organising and undertaking domestic works, such as extensions, maintenance, and refurbishment, have an important role in influencing how homes are configured and how occupants live within them. Despite this, the professional identities of these actors, and their impact on domestic energy use, is often overlooked. In response, this paper argues that one useful way of examining their influence is to consider how professional identities shape everyday working practices in relation to clients. Data from two UK interview and observation studies are combined: one with heating installers and one with architects. The data are analysed using concepts from Abbott’s ‘system of professions’ framework that focuses on how the routine working practices of professional groups are born of how they see themselves and the tasks for which they are responsible. This comparison provides insights into how these two groups manage their professional ‘jurisdictions’ during their client interactions and what this means for policy makers and industry representatives hoping to influence their work in pursuit of less carbon intensive living. It also points to the value of further in-depth studies that explore how the routine management of professional jurisdiction impacts upon domestic energy use in a range of contexts.