District heating (DH) consists of substantial energy infrastructures in many urban areas around the world, which offer a significant opportunity for achieving economies of scale and increasing the energy efficiency of the built environment. Heat networks have been identified by the UK Government as an essential mechanism for decarbonising heat. However, different to other European countries, the UK heat network market is minimal, meeting only around 3% of overall heat demand. Many of these networks use Combined Heat and Power (CHP) technologies, often driven by carbon-intensive gas engines. If the UK is to achieve its netzero target, these CHP systems need to be modified or replaced with low-carbon alternatives such as heat pumps. One challenge to the growth of low-carbon heat networks in the UK relates to a lack of clarity when categorising them as either communal or district. These systems have different merits and peculiarities that affect their potential as scalable tools for decarbonisation. This paper aims to address this challenge by proposing new definitions that clearly separate district and communal concepts. This is achieved by analysing the status of heat networks in the UK and London, which is complemented by a review of current definitions available in the literature. The potential implications of misclassification to the development of DH in the UK are then discussed, with a focus on how policy needs to establish clear boundaries in order to guide the transition towards a low-carbon DH market in the UK. By addressing the issue of inconsistent categorisation and improving data accuracy, this paper serves as a foundation for future research and development efforts aimed at overcoming the barriers to the broader deployment of low-carbon heat networks in the UK
