CAD to BIM

CAD to BIM

Turns the CAD drawings in your Revit project into real Revit content. The lines on a drawing's layers become walls, floors, ceilings, roofs, columns, beams, grids, ducts, pipes, cable trays and other runs. Every repeated block becomes one clean, light family, placed at each spot it appears in the drawing, turned and mirrored the way the block was. Everything is checked first and can be tried in a rollback trial before anything stays in the model, the whole conversion is one Revit undo step, and the original drawing is never changed.

When to use it

• An imported or linked DWG plan has to become a working Revit model: walls from wall layers, floors and ceilings from closed outlines, columns and beams from the structure layers.
• A furniture, equipment or fixture layout drawn as CAD blocks - or as plain lines - should become Revit families: one tidy family per identical shape, with the right count of instances.
• MEP centrelines on the drawing should become connected duct, pipe, conduit or cable tray runs with their fittings.
• You converted part of a drawing before and need to run it again after the drawing changed, replacing only what the plugin created last time.

How to use

1. Open CAD to BIM from BimCode's plugin list inside Revit, with the project that holds the imported or linked CAD drawing.
2. Scan CAD. The plugin reads every CAD drawing in the project (or only the ones you selected in Revit) and lists its layers, blocks and curves. Nothing in the model changes.
3. Choose a workspace. The top switch has two:
   • Bulk & network studio - the CAD catalogue for whole layers and every block at once, the mapping studio for one rule at a time, and the MEP network for connected services.
   • Classic CAD studio - a large drawing preview with coloured layers and CAD text, layer-by-layer mapping, wall and opening detection and MEP size detection.
4. Map. Pick what each layer or block becomes: a wall type, a floor type, a duct type, a family from the project, a family file, or a new family built from a family template.
5. Validate, then run a Rollback trial. The trial really creates everything in Revit and then takes it all back, so you can read exactly what would happen in Audit.
6. Validate again and Create in Revit. One undo step removes the whole conversion if you change your mind.

Blocks to clean families

On the CAD catalogue page (Blocks → families), each block is tidied the way you would tidy it by hand in AutoCAD before it becomes a family, in seven steps:

1. Find blocks - Level 1 (the blocks placed straight in the drawing, with everything inside them) or Level 2 (the blocks nested one level inside those).
2. Loose lines as blocks - furniture drawn as plain lines rather than blocks is picked up too: lines that touch become one shape, and identical shapes share one family.
3. Clean before - lines drawn twice and overlapping lines are removed, as AutoCAD's purge and overkill would. The default, Exact, never moves or reshapes a line; Light and Strong make lighter families.
4. Make as - the cleaned block as a CAD import, as detail lines or as model lines, with the family origin at the centre of the block. Arcs and circles stay true arcs.
5. Family names - a prefix and a suffix for every family, with the drawing's file name and anonymous block names tidied automatically.
6. Tidy after - each family is cleaned again, purged of unused items and saved compact; CAD layers can become family subcategories.
7. Lines that are not blocks - the rest of the drawing can come in as detail or model lines, cleaned the same way, in the same undo step.

Click a row to see its clean-up before and after, with the number of pieces removed. Run the catalogue again later and the families it made earlier are updated in place; copies already placed stay exactly where they were.

Good to know

• Your drawing stays as it is. The plugin reads the CAD import or link; it never explodes, edits or deletes it, and never saves the project for you.
• One family for repeated blocks. Twelve identical desks become one desk family with twelve instances. Blocks at a different scale or with different content stay separate.
• Families made by others are safe. A family the plugin did not make is never overwritten; a new name is proposed instead.
• Original block content needs AutoCAD. Keeping a block's original text and hatches inside the new family needs AutoCAD or Civil 3D installed on this computer and the CAD to BIM extraction helper installed for it. Without them, the plugin rebuilds each block from the lines Revit can see, or makes DirectShapes - text and hatches are then left out.
• Hosting is real or not at all. A wall- or ceiling-hosted family is placed on an actual wall or ceiling found under it. A family that cannot be placed correctly makes the whole run roll back with an explanation, rather than landing in the wrong place.
• Values are examples, not engineering. The MEP heights and sizes the plugin suggests are starting points to edit, not calculated design.
• Revit versions. Works in Revit 2025, 2026 and 2027. Property lines from CAD need Revit 2027.

The full walk-through is in docs/USER-GUIDE.md.

AutoCAD and Civil 3D are trademarks of Autodesk, Inc.