Master planned estates have been the subject of considerable academic interest since the publication of Blakely and Snyder's () typology. The growing provision of private assets, facilities, and infrastructure in such estates has been documented and discussed. However, the extent of this form of residential estate in Australia has yet to be systematically documented. This paper seeks to contribute to knowledge in this field by reference to findings from an investigation in Sydney, Australia, using data from 300 private residential estates constructed under the New South Wales Community Land Development Act, 1989 (community title) over a 20-year period. The aim is to understand the broad trends emerging in relation to the nature and extent of these types of developments and to consider some of their potential implications. This research suggests that there has been a quiet revolution in residential development and postulates that the extent of privatisation of essential neighbourhood infrastructure has been considerable. The study finds that master planned residential estate development has proliferated, particularly in the outer suburbs and in areas of relative disadvantage, and resulted in enclaves of comparative affluence disconnected from surrounding areas. In addition, the restrictive covenants usually applied in these estates are often designed to prevent change, including future densification or environmental adaptation. To this extent, the privatised nature of these estates puts them beyond the reach of broader urban planning goals.