Abstract: Architecture is located at the confluence of international capital flows, urban hierarchies and national discourse, constructed according to the globally oriented agendas of local bureaucrats, against measures of ‘the global’, including design excellence, competitive processes, and international expertise. Under such perceived conditions of globalisation, academics and policy makers alike have often been preoccupied with defining norms to frame how we understand architectural forms in global cities. As a consequence of reductive understandings, any substantial acknowledgement of the complex relations and interdependencies that shape the process of constructing global architecture is typically negated. Understandably, some researchers have cautioned against accepting and deploying rationalised views of globalness, arguing that urban researchers need to adopt innovative approaches to understand the complexity of the city and its forms (McCann et al., 2013). Assemblage thinking offers a tool to explore the complexity of the city by attending to the intricacies of the practices of planners, as they are embedded in and influenced by variegated historical, social and material contexts. To be sure, urban research needs to take notice of what urban actors ‘do’ as they engage in global city-building, as much of what takes place in everyday practice is as yet un-theorised (Healey, 2012). Informed by my research on the practices of how city builders materialise architecture in Global Sydney, this paper thus argues that deploying assemblage thinking – with the analytical attention that it is able to afford to practices – is able to challenge the hegemonic claims of orthodox approaches to understanding architecture in the global city. More broadly, I argue that adopting assemblage thinking can disrupt the ontologies that have shaped urban research on architecture by opening up a geographic dialogue that is able to acknowledge the hybridity of the process of how globalness is constituted, in practice.