Direct Answer
Scan-to-BIM uses 3D laser scanning (LiDAR) to capture the as-built geometry of an existing structure and converts the point cloud data into a 3D BIM model. For steel fabricators working on renovation or expansion projects, scan-to-BIM reveals actual field conditions — column locations, beam elevations, slab thicknesses — that may differ significantly from original design drawings.
Full Explanation
The workflow: (1) A surveyor scans the existing structure with a terrestrial LiDAR scanner, producing a dense point cloud (millions of points representing the 3D surface). (2) The point cloud is registered to the building coordinate system. (3) A modeler traces structural elements from the point cloud to create an as-built Revit or Tekla reference model. (4) The new structural design is coordinated against the as-built model to identify conflicts before fabrication. For renovation projects, this process prevents the costly discovery of as-built deviations in the field after steel is already cut.
What This Means for Your Shop
On renovation projects, request a scan-to-BIM deliverable before any detailing begins. Renovation projects without as-built scanning regularly encounter field conditions that require 20–40% more RFIs and field modifications than new construction.
Common Mistakes
Relying on original design drawings for renovation projects without verifying against actual field conditions. Original drawings may be 30 years old and may not reflect any of the modifications made since original construction.
Recommended Process
Include scan-to-BIM as a line item in renovation project estimates when existing-condition verification is critical. Tectonix can coordinate LiDAR scanning and as-built modeling as part of a renovation detailing engagement.