Understanding the term urban sustainability continues to dominate discourse in the built environment as societies explore how cities can be considered sustainable. Due to the increasing rate of urbanization, scholars argue that the battle for sustainability will be won or lost in cities; recognizing the crucial role that neighbourhoods can play as building blocks of urban areas. However, while the context-specificity of the several approaches to sustainability at the neighbourhood level has been recognised, no single accepted understanding of a sustainable (...) neighbourhood has emerged. This paper explores institutional stakeholders’ understanding of a sustainable neighbourhood using questionnaire data from metropolitan Lagos. This aligns with the critical realism philosophical stance which believes that knowledge can be sourced through the perception of people with respect to an underlying structure based on their reality. The findings show variations in the perceptions with institutions having similar responsibilities differing in their understanding of the concept. It was unclear why a single common understanding was missing and why certain elements were more emphasised than others even in institutions having similar roles. Further research should explore the mechanisms at play in influencing these understandings and how they may differ in various urban contexts in Sub-Sahara Africa. (shrink)