Abstract: Public participation in planning assessment in Australia emerged in the context of social and political changes of the 1970s. Increasing criticisms of planning in the rational comprehensive model fuelled by opposition to large-scale construction and demolition, along with the perception of close alliances between developers, investors and State Governments, led to widespread calls for greater consultation in the planning process. Significant community opposition originated in battles over planned destruction of affordable and social housing and green spaces as epitomised in Sydney’s Green Bans. By the end of the decade, a reassessment of planning policies at the Federal and State levels saw new directions in land use planning towards the incorporation of public opinion and third party objection and appeal processes in planmaking and planning approval processes. The transition to participatory planning processes is one of the key characteristics of urban planning in the latter part of the 20th century. The nature and extent to which planning policy and practice have incorporated participatory mechanisms varies, as does debate over their desirability and merit (Allmendinger & TewdwrJones 2002). However, the influence of participatory goals are keenly felt across planning’s recent history. This is perhaps most evident in the wide-ranging contribution of planning theorists to debate around communicative rationality, deliberative democracy and agonism (Hillier & Healey 2011). But it is also evident in earlier calls for ‘transactive’, ’social learning’ approaches embedded in Friedmann’s post-Euclidean planning (1993) and Sandercock’s (1998) discussion of multiple publics. A myriad of planning policies in Australia and further afield have prioritised consultative approaches since the turn of the century. Sandercock (1998) argues that the economic and social complexity of cities along with the ‘rise of civil society’ and feminist and post-colonial politics set the scene for more deliberative planning approaches. The complexity of urban life challenged the idea of a coherent or absolute ‘public good’. Civil protest has also formed a prevalent motif in planning histories as a trigger in the reconfiguration of planning roles from ‘presumptive public interest’ towards advocacy (Friedmann 1998: 20) and deliberative models (Healey, 1997). However, the relationship between non-experts and planning reform in Australia in the 1970s occupies an ambiguous position in planning history. While there is some consensus across key texts in planning history that non-experts have influenced aspects of urban governance, politics and urban environmentalism (Freestone 2010; Freestone 2007; Thompson 2007; Gleeson and Low 2000), the impact of non-experts on planning― including planning policy and planning law― remains unspecified. The implication of this ambiguity is that many of the agents gathered in the achievement of significant planning reform may remain unacknowledged. As calls for planning reform gain momentum (Steele and Gleeson 2009; Hillier 2011) an interrogation of the hidden relationships underpinning moments of significant planning reform is urgently required. Taking as its case planning reform in NSW in the late 1970s, this paper aims to address this gap. At the beginning of the decade, significant community opposition emerged in battles over planned destruction of affordable and social housing and green spaces epitomised in Sydney’s Green Bans. By the end of the decade, a reassessment of planning policies at the Federal and State levels saw new directions in land use planning towards the incorporation of public opinion and third party objection and appeal processes in planmaking and planning approval processes. Drawing on historical materials documenting the interaction between resident action groups, non-government organisations, unions, planners and politicians from 1971- 1979, the paper explores the emergence of planning reform towards the incorporation of public viewpoints. Specifically, this paper argues that residents and non-experts played a key role in the reform of the NSW planning system through the centralisation of public participation in the objects of the EPA Act, and the development of third party rights. SITUATING PARTICIPATORY PL