The Scan to BIM workflow, step by step

1. Scope the project

Start with the use of the model, not the model. A renovation design team, an MEP contractor and a facilities manager need very different things from the same building. Write down:

• The areas and disciplines in scope (architecture, structure, MEP, process, site).
• The LOD per discipline (see LOD levels explained) and the LOA per element (see how to write a Scan to BIM specification).
• The deliverables: Revit version, IFC version, drawings, families, naming standards.
• The coordinate system and survey control to tie into.
• The deadline, and who reviews and accepts the model.

2. Plan the scan

A scanner only measures what it can see. Plan positions or routes so every surface in scope is seen, ideally from more than one direction. Think about ceiling voids, plant rooms behind locked doors, risers, roofs and anything that needs access equipment. Decide the scanner type for each area (see choosing a scanner) and when the site will be quiet: people and vehicles moving through a scan create noise that has to be cleaned out.

3. Capture

Terrestrial scanners capture from fixed tripod positions; mobile and handheld SLAM devices capture while walking. Whichever you use, set or record survey control (targets or known points) if the model has to sit in project or site coordinates, and capture photography for context. Keep a scan log: positions or routes, times, and anything that could not be accessed.

4. Register and clean

Registration aligns the individual scans into one point cloud in one coordinate system. It is usually done in the scanner vendor's software or in Autodesk ReCap Pro. Ask for the registration report: it states the errors between scans and against control, and it is your first quality check. Misregistration shows up later as doubled walls. Then clean the cloud: remove people, vehicles, reflections and stray points. Export a full-resolution E57 plus the format your modeling tool needs (see point cloud file formats).

5. Model

Modeling is where most of the time goes. In a manual workflow the modeler links the cloud in Revit, sets levels and grids, then traces walls, floors, openings, structure and MEP against it, as covered in how to convert a point cloud to Revit. Tools such as FARO As-Built, ClearEdge3D EdgeWise and ReCap Pro's segmented meshes speed up parts of this. Automated services segment the cloud into objects and build the model directly, with people reviewing the result. How AI is automating Scan to BIM explains how.

Whatever the method, keep to the brief: model to the LOD asked for, flag anything inferred rather than measured (hidden geometry behind finishes, for example), and keep the model in the scan's coordinates.

6. Check against the scan

Before delivery, compare the model with the point cloud. A deviation analysis colour-codes how far each modeled surface sits from the measured points and shows whether the agreed LOA is met. Spot-check critical dimensions and openings. How to check a Scan to BIM model against the point cloud gives a checklist.

7. Deliver

Issue the model in the agreed formats, normally Revit plus IFC (see IFC or Revit?), with the registered cloud, a short report (scope, LOD and LOA achieved, inferred areas, known gaps) and any drawings. Version the deliverables so later updates can be tracked.

How long each stage takes

If you already have a registered point cloud, you can upload a scan today and receive Revit and IFC with every object separated within 48 hours. For pricing context see the Scan to BIM cost guide.

Frequently asked questions