Responding to the climate crisis in the UK is likely to entail changes to citizens’ everyday activities, as well as corresponding changes to transport, housing, and business practices. This thesis uses a practice theory lens to investigate these low-carbon changes, in the specific context of a UK eco-town (Cranbrook). Cranbrook’s original ambitions to be a low-carbon eco-town are in evidence from its early planning documents. Using Cranbrook as a case study, low-carbon practices are investigated in five key areas. These are: 1) transport, 2) energy, 3) heat and buildings, 4) waste and recycling, and 5) green spaces and miscellaneous practices. These are examined both in terms of local residents’ practices and in terms of stakeholders’ and policymakers’ practices. Using questionnaires, interviews, and document analysis methodologies, the eco-town is investigated to discover the extent to which it has achieved its original low-carbon ambitions. The thesis concludes that the average carbon footprint amongst eco-town residents is unlikely to be significantly different to the UK average (based on the self-reported data described above). This thesis makes contributions to academic research on low-carbon lifestyles, practice theoretical sustainability interventions, and eco-homes and eco-towns, by demonstrating how the eco-town in question does not yet live up to its full sustainable potential. This is due to a number of factors, including: minimal locally-available services or jobs (leading to extensive private car use), technical difficulties around finding a low-carbon fuel source for the district heating system, and problematic roll-backs of building fabric and energy-efficiency regulations. The eco-town is, however, found to have good foundations for future decarbonisation initiatives, such as excellent internal pedestrian and cycle access, strong community bonds between residents, a growing culture of upcycling practices, and well-maintained popular public green spaces. The case study results can be partially generalised to other planned and/or built UK eco-towns, showing the importance of policymakers taking further steps to decarbonise these.