Scan to BIM and CAD to BIM in Singapore: Choosing the Right Conversion Workflow

Existing buildings and legacy projects often begin with incomplete digital information. Scan to BIM converts measured survey data such as point clouds into a structured model, while CAD to BIM converts suitable two-dimensional drawings into a model. These workflows can look similar in a final Revit file, but their evidence base is different. A point cloud reflects captured physical conditions within the limits of the survey, while old drawings may reflect design intent, previous records or outdated conditions.

Define the scope before production starts

Define why the converted model is needed before deciding how much to model. Possible uses include renovation planning, space coordination, asset documentation, existing-condition drawings, design reference or future BIM coordination. Agree the areas, elements, required model detail, information fields, coordinate system, tolerance expectations and whether uncertain or inaccessible conditions need to be flagged rather than guessed.

A practical delivery workflow

For Scan to BIM, the team should review point-cloud coverage, registration information, coordinate setup and areas of poor visibility before modelling. For CAD to BIM, drawings should be checked for revision status, dimensions, consistency between plans and sections and whether field verification is available. The model is then produced in controlled zones or disciplines with review checkpoints before the whole conversion is completed.

Quality and coordination checks

Quality control should distinguish model precision from source accuracy. A Revit element can be modelled very precisely from an inaccurate old drawing, while a point cloud can contain noise or inaccessible areas. The deliverable should therefore state the source, agreed tolerance or interpretation rules, exclusions and any parts that require project-team verification. This is especially important when converted information will influence new construction or services coordination.

Singapore project context and responsibilities

Singapore alteration, addition and existing-building projects may combine surveys, old CAD records, site mark-ups and consultant information. BIMProSG can provide conversion and modelling support from supplied source data, but it does not replace licensed surveying, professional design verification or statutory responsibilities where those are required. The project team should appoint the appropriate professionals for measurement, design and formal submissions.

Commercial and engagement considerations

Pricing depends on floor area or model extent, source-data quality, disciplines, element complexity, required information, modelling tolerance, number of review cycles and expected outputs. A cheap conversion based on ambiguous sources can create false confidence, so exclusions and assumptions should be explicit in the quotation.