A manufacturing organisation in India contemplated augmenting their capacity and took up a green-field expansion project in a new location. The internal construction division of the organisation decided to introduce Lean construction philosophy. A study was taken up to understand the impact of Lean on the engineering, procurement and construction phases where multiple stakeholders who are entrenched in traditional approaches are involved. A detailed case study and action- based approach was adopted. The data included both primary observation data collected by the researchers present in meetings and other data from various reports. . There were some interesting insights into the dynamics involved when groups with diverse approaches are brought together on a Lean construction journey. There was also a challenge of implementing Lean with multiple project teams all working in the same organisation and therefore with little or tacit contracts involved in the project. The initial attitudes of the people which ranged from enthusiasm to outright scepticism and engagement with reservations evolved progressively over time to embracing Lean in varying degrees and formats. The complexities present in the organisational structure contributed to the formation of institutional voids which were leveraged by the Lean group to promote Lean practices.