Reduce Revit file size,
in the right order.

Step 1 - imported CAD (the big one)

Imported DWGs bring every layer, line style and hatch into the project as permanent object styles, and imports nested inside families are copied into every project that loads them. Revit gives you no single list of them. Parapet Audit (free) does:

• Sort by weight; delete imports that appear on no sheet - confirmation shows exactly what goes, one undo.
• Replace surveys and consultant backgrounds with links on their own workset, visible only where needed.
• Open families that carry imports, retrace with native lines, reload.

Full guide: find and remove imported CAD.

Step 2 - purge, then purge what purge leaves

Manage → Purge Unused twice (the second pass catches what the first freed). Then delete leftover imported line patterns (Manage → Additional Settings → Line Patterns, anything named “IMPORT-…”), fill patterns and object styles under Imported Objects.

Step 3 - views, sheets, overrides

Every view regenerates graphics and keeps overrides. With Parapet Hub: Delete unplaced views, Delete empty sheets, Reset overrides, Reset temporary hide/isolate, Remove view template on working views that don't need one.

Step 4 - warnings, then compact

Warnings cost regeneration time, not megabytes, but they travel together. Hub's Select warning elements plus Find duplicates at the same location, Unjoin, Delete unplaced rooms clears the usual suspects. Finally Save As → Options → Audit + Compact File.

Before / after, typical

Indicative numbers from real projects; yours depend on the model.