Contemporary research on urban systems looks at resilience as a framework to produce policies and projects that better integrate urban planning and design to make cities more capable of responding to sudden perturbations, to adapt to long-term future changes and to achieve higher levels of sustainability over time. Green infrastructure is recognised as a non-traditional approach to deliver a wide set of ecosystem services in cities and is increasingly recognised as a way to operationalize concepts of urban resilience through better delivery of urban planning and water sensitive urban design. This paper argues that the first step in delivery of effective Green Infrastructure planning and the improved delivery of ecosystem services is the identification, calculus and visualisation of the full spectrum of urban green space. In this research, three diverse case study cities – Rome, Sydney and Hanoi – were selected for their diverse geographical origins and planning history and the identification of a spectrum of Green Infrastructure types made via a transect mapping exercise. This revealed a diversity of public parks and plazas, streetscapes, terrain vague and domestic gardens and through analysing these cities urban fabric we propose how these identified spaces could theoretically deliver a range of beneficial ecosystem services for greater urban resilience, particularly concerning the increased adaptation capacity to climate change that can be obtained by multifunctional Green Infrastructure. We then considered the existing planning rules, strategies and mechanisms within each city, comparing the potential to better recognise and activate these spaces as critical pieces of overlooked green infrastructure into the metrics of a sustainable and resilient future city.