Critical success factors for adopting building information modelling (BIM) and lean construction practices on construction mega-projects: a Delphi survey Martin Evans University of Calgary, Calgary, Canada Peter Farrell University of Bolton, Bolton, UK Ayman Mashali Mansoura University, Mansoura, Egypt, and Wael Zewein Edinburgh Napier University, Edinburgh, UK Abstract Purpose – The purpose of this paper is to investigate critical success factors (CSFs) that enhance integration between building information modelling (BIM) and lean construction (LC) practices on construction mega- projects. BIM and LC have gained momentum in the past decade. Design/methodology/approach – The Delphi survey technique was used to gauge opinions of a panel of 16 experts through a two-round Delphi questionnaire survey. Panel responses were scrutinised using inferential and descriptive statistical techniques. Findings – In total, 30 CSFs were identified in the literature. The top ranked factor out of 30 that supports LeanBIM synergy was “collaboration in design, construction works and engineering management”. Other top rated CSFs were centric on people, data and technology elements. The research findings are important for project stakeholders, organisations, contractors, engineers and local authorities who implement LC and BIM synergies in construction mega-projects. Originality/value – The research findings are important for project stakeholders, organisations, contractors, engineers and local authorities who implement LC and BIM synergies in construction mega- projects. The research recommends further hands-on training to increase the integration of BIM and LC practices in the architecture, engineering and construction industry and to enrich the extant body of knowledge in construction of mega-projects. Keywords Lean construction, Building information modelling, BIM, Critical success factors, Mega-projects, Construction industry, Built environment, Delphi study Paper type Research paper 1. Introduction The construction of mega-projects is complex, and includes numerous interrelated processes (Mashali et al., 2020a; Olawumi and Chan, 2018). The complexity requires a smart, innovative technologies to coordinate construction challenges that arise on most Critical success factors Received 23 April 2020 Revised 26 May 2020 Accepted 10 August 2020 Journal of Engineering, Design and Technology © Emerald Publishing Limited 1726-0531 DOI 10.1108/JEDT-04-2020-0146 The current issue and full text archive of this journal is available on Emerald Insight at: https://www.emerald.com/insight/1726-0531.htm