Revit Tip: CAD Cleanup and Linking Best Practices for Revit

Dirty CAD files slow modeling, corrupt standards, and bloat your Revit project. Clean every CAD file before linking or tracing over it to protect accuracy and performance. If you need software, plugins, or workflow advice, consult the experts at NOVEDGE.

Pre-import cleanup in CAD (essential):

• Units and scale: Verify UNITS and drawing units are correct; set INSUNITS consistently. Confirm your target Revit units match expectations.
• Audit and purge: Run AUDIT, then -PURGE (including Regapps) until nothing remains. Use OVERKILL to remove duplicates and tiny segments.
• Flatten geometry: FLATTEN all to Z=0 for plans/elevations; remove 3D artifacts that can cause strange snaps and view depth issues in Revit.
• Simplify: Convert SPLINEs to polylines, explode complex hatches, erase dense patterns, and delete unneeded annotation (dims, text, leaders).
• Blocks and proxies: Resolve AEC objects and proxies (EXPORTTOAUTOCAD or set PROXYGRAPHICS=1), then explode overly nested blocks you plan to trace.
• Layers: Consolidate to a minimal, logical set (e.g., walls, grids, doors). Assign ByLayer colors/linetypes and remove unused layers/linetypes.
• Extents and origin: Ensure the model is near 0,0 and within reasonable extents; WBLOCK out only the area you need to reduce file size.
• Xrefs: Bind or, better, ETRANSMIT to a clean, single file. Eliminate image underlays unless absolutely necessary.

Best practices when bringing CAD into Revit:

• Always Link CAD (do not Import) for control and to avoid embedding baggage into the RVT.
• Positioning: Prefer Auto – Origin to Origin after you’ve aligned CAD to a clean origin; avoid Center to Center on production work.
• Units: Set a known unit rather than Auto-Detect to prevent subtle scale errors.
• Visibility: In the link dialog, choose Black and White, Disable Smooth Lines, and Current View Only for tracing views.
• Worksets: Place CAD links on a dedicated “CAD_Links” workset; default it off in templates. This keeps heavy links out of most views.
• Pin immediately and set to Halftone/Underlay in View Templates. Manage layers via Visibility/Graphics > Imported Categories as needed.

Exploding CAD in Revit (rare and careful):

• Avoid exploding in model views. If you must for 2D details, do it in a Drafting View and use Partial Explode only.
• Immediately purge resulting line styles, patterns, and materials; remap to your office standards.

QA checks before modeling over CAD:

• Dimension a few critical spans to confirm scale and orthogonality (90°, 180°). Misaligned geometry leads to constraint and warning cascades.
• Check for very long extents warnings; crop or replace the link if present.
• Verify critical datums (grids, levels in elevation) align with Revit references before tracing walls, doors, and structure.

Tip: Maintain a “CAD Intake Checklist” in your project template and train teams to follow it. For Revit licenses, add-ons, and training resources, visit NOVEDGE. Need help optimizing your CAD-to-Revit pipeline? Reach out to the NOVEDGE team for guidance.