Purpose
Building information modeling (BIM) offers numerous benefits for construction projects, but its implementation can include additional non-physical costs, commonly referred to as soft costs, distinct from traditional construction projects. Hence, understanding the soft cost elements (SCEs) is critical for accurate cost estimation in BIM-based construction projects. This study aims to identify the critical SCEs in BIM-based construction projects.

Design/methodology/approach
This study conducted a multi-stage approach, starting with an SLR to compile an initial list of SCEs, which was refined through a pilot test with BIM experts. A Delphi survey conducted with 16 experts evaluated the SCEs for two rounds. Data analysis included mean values and percentage of agreement analyses to identify the critical SCEs. Finally, a thematic analysis was conducted to categorize the critical SCEs.

Findings
This study identified eight critical SCEs in BIM-based construction projects, categorized into two categories: technology and human resources. Technology-related costs include BIM software, hardware, updates and BIM-specific planning/designing. Human resource-related costs encompass BIM consultant, modeler, coordinator and manager remuneration.

Originality/value
This is the first study to determine the critical SCEs in BIM-based construction projects. Understanding the critical SCEs provides stakeholders with actionable insights for developing strategies to improve the cost management of SCEs in BIM-based construction projects.