BIM consultancy cost formation in design-stage public projects: evidence from Vietnam.

Abstract

This study examines the structure and estimation of Building Information Modelling (BIM) consultancy cost estimates in public construction projects. While BIM adoption is expanding rapidly, limited empirical evidence exists on how BIM-related costs are structured in practice, particularly in consultancy-driven project environments. Using a multiple case study approach, the research analyses BIM consultancy cost estimation reports from four public construction projects in Vietnam, focusing on design-stage implementation. The study investigates the composition of BIM consultancy costs, the allocation of BIM personnel roles, and the factors influencing cost estimation practices. The findings indicate that BIM cost estimates are primarily driven by labour inputs associated with BIM managers, coordinators, and modellers, while software licences and technical resources constitute a relatively small share of the overall consultancy budget. The results further show that project complexity, implementation stage, procurement arrangements, information requirements and scope specification significantly influence BIM cost estimation. By providing empirical evidence derived from approved cost estimation documents used in project planning, this study contributes to a clearer understanding of BIM cost estimation structures as governance-dependent processes and offers practical insights for project owners planning BIM implementation in consultancy-driven construction environments.