Master-planned estates (MPEs) are proliferating as an urban residential form, particularly in the rapidly expanding urban fringes of Greater Metropolitan Sydney, Melbourne and South East Queensland. As crucibles of urban change, MPEs have the potential to reshape urban residential structures and refashion ways of relating in urban residential neighbourhoods. They thus require more rigorous analysis: as an empirical phenomenon; as a new social formation; and as a manifestation of the privatisation of the public realm. Australian urban researchers have begun to turn their attention toward the MPE. This paper critically engages with these understandings of master-planned estates (MPEs) in the Australian context. We argue that the conclusions about the nature of the MPE phenomenon are currently limited because they are drawn from a narrow range of case studies of just one form of MPE: the master-planned community. Based on a preliminary analysis of findings emerging from our research into MPEs in the Greater Metropolitan Region of Sydney, we sketch the diversity of MPE forms that are emerging. From this we suggest the need for a more robust analytical framework and, drawing on Sydney examples, sketch the dimensions such a framework needs to consider. These will be necessary to guide analysis of the complex development and governance processes that underpin MPEs, as well as analysis of the varied patterns of sociability their different forms are likely to produce. We argue, therefore, for a broader theoretical and empirical scope for the research agenda and tentatively suggest directions for that agenda.