ABSTRACT Australia is one of the most urbanised countries, and its states and territories are facing significant environmental threats. This paper argues that urban planning authorities in the Australian state of New South Wales (NSW) repeatedly abandon their carefully crafted urban policies that could have improved environmental sustainability. This qualitative research analyses two cases, nearly two decades apart, to support its argument. In 2021, the NSW planning department developed significant reforms to planning laws, namely the Design and Place State Environmental Planning Policy (SEPP). This set of proposed rules would have made planning, placemaking, and communities more liveable and sustainable. In April 2022, the proposed policy was suddenly and unexpectedly scrapped. The recent abandonment of a well-thought-out planning policy proposal in NSW is not unprecedented. It is a case of history repeating itself. In 2003, the PlanFirst sustainability-related planning reforms that had been developed over several years were abandoned similarly. This paper uses the path dependency theory to explore the repetition and discarding of sustainability-related planning reforms. This paper shows how politics and policy making in NSW have neglected significant policies designed to improve environmental sustainability and liveability following property developer lobbyists’ influence.