Originating from a disenfranchisement with the contemporary definition and realisation of Westernised architecture as a commodity and product, this thesis seeks to explore alternative examples of positive socio-spatial practice and agency. These alternative spatial practices and methodologies are drawn from participatory and grass-roots development agency in informal settlements and contexts of economic absence, most notably in the global South. This thesis explores whether such examples can be interpreted as practical realisations of key theoretical advocacies for positive social space that have emerged in the context of post-Second World-War capitalism. The principal methodological framework utilises two differing trajectories of spatial discourse. Firstly, Henri Lefebvre and Doreen Massey as formative protagonists of Western spatial critique, and secondly, John F. C. Turner and Nabeel Hamdi as key advocates of participatory development practice in informal settlements. These two research trajectories are notably separated by geographical, economic and political differentiations, as well as conventional disciplinary boundaries. However by undertaking a close textual reading of these discourses this thesis critically re-contextualises the socio-spatial methodologies of participatory development practice, observing multiple theoretical convergences and provocative commonalities. This research proposes that by critically comparing these previously unconnected disciplinary trajectories certain similarities, resonances and equivalences become apparent. These resonances reveal comparable critiques of choice, value, and identity which transcend the gap between such differing theoretical and practical engagements with space. Subsequently, these thematic resonances allow this research to critically engage with further appropriate surrounding discourses, including Marxist theory, orientalism, post- structural pluralism, development anthropology, post-colonial theory and subaltern theory. 5 In summary, this thesis explores aspects of Henri Lefebvre's and Doreen Massey's urban and spatial theory through a close textual reading of key texts from their respective discourses. This methodology provides a layered analysis of post-Marxist urban space, and an exploration of an explicit connection between Lefebvre and Massey in terms of the social production and multiplicity of space. Subsequently, this examination provides a theoretical framework from which to reinterpret and revalue the approaches to participatory development practice found in the writings and projects of John Turner and Nabeel Hamdi. The resulting comparative framework generates interconnected thematic trajectories of enquiry that facilitate the re-reading and critical reflection of Turner and Hamdi's development practices. Thus, selected Western spatial discourse acts as a critical lens through which to re-value the social, political and economical achievements of participatory development. Reciprocally, development practice methodologies are recognised as invaluable and provocative realisations of the socio-spatial qualities that Western spatial discourse has long advocated for, and yet have remained predominantly unrealised in the global North.