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Compare revisions

Overlay, side by side and flicker, detect changes, carry markups forward, change pricing.

See what changed between two issues of a sheet, cloud the changes, carry your markups to the new revision and price the difference. Comparing is available in every profile; change pricing needs an estimating profile.

How to start a comparison

  1. Open both revisions, the previous one and the new one. (You can also open the old one from the panel with Open file as base….)
  2. Review → Compare revisions… opens the Compare panel.
  3. Choose Base (previous): file and page, and Revised: file and page. Match page finds the base page that shares the most words with the revised page.
  4. Click Compare.

The base sheet is aligned onto the revised sheet automatically (first by matching text, then by the sheet border and grid lines). The results are saved in the revised file.

Alignment

The Align tab shows how the sheets were aligned: the method, the number of anchors, the residual (how far apart matching points still are, in points), and the transform (scale, rotation, shift; sheets are never stretched or skewed). The status bar shows a Compare chip with the residual (e.g. "Compare 0.42 pt"): green when verified, amber when you confirmed it yourself, red when not aligned.

  • Verified: you can go ahead.
  • Unverified: check the overlay. If it looks right, click Use this alignment. If not, use Align with 3 points…: click three distinct features far apart on the base sheet (corners, grid intersections), then the same three, in the same order, on the revised sheet.
  • Align automatically runs the automatic alignment again.

Scanned sheets are aligned with image patches; three points help them most.

View modes

In the panel or the Review menu:

  • Overlay: both sheets on top of each other, the base in red and the revised in blue. What is on only one of them stands out in its colour.
  • Side by side: the two sheets next to each other, scrolling and zooming together.
  • Flicker: switches between base and revised (Pause / Resume). Toggle base / revised (Ctrl+Alt+F) steps by hand.

How to detect changes

  1. Review → Detect changes (or the Changes tab).
  2. Options: Create revision clouds (layer "Changes"), Ignore other apps' markups (e.g. Bluebeam), Resolution.
  3. The result lists the changed areas (Added, Removed, Modified, Moved) and the text changes word by word (e.g. Text "100A" changed to "125A"). Click one to go there.

If hundreds of areas are found, the alignment is probably wrong: no clouds are created then. Align again and repeat.

Revision summary in the Changes tab writes a short summary From the data. With AI turned on, AI summary writes one in plain words; check every point against the drawings.

How to carry markups forward (slip sheet)

  1. Review → Slip sheet: carry markups forward… (or the Slip sheet tab).
  2. Choose which markups to bring: by Layers, Types, or Takeoff items only.
  3. Click Carry N markups forward.

The copies land on the revised sheet in the right place and are tagged for review; copies touching a changed area are flagged. Right-click a carried markup → Accept carried markup or Reject carried markup (delete), or use Accept all outside changed areas / Accept all in the tab. Takeoff data (panels, circuits, unit types, viewport calibrations) is copied along.

Change pricing (estimating profiles)

  1. Carry the takeoff forward and update it on the revised sheet.
  2. Takeoff → Change pricing (revision deltas)… (or the Pricing tab) → Compute deltas.
  3. The table lists each item's base and revised quantity and its status (To review, Accepted, Rejected). Quantity changes where the drawing did not change are flagged "outside detected changes": check them.
  4. Find symbols in changed areas searches added and modified areas for the base page's counted symbols; the proposals are counted only when accepted.

This is a draft for review: frozen estimates and purchase orders are never changed.

Impact

The Impact tab lists what lies inside changed areas on both sheets: linked iCOS records (RFI, QA/QC, tasks), takeoff items and carried markups.

Whole sets at once

Batch → Batch slip sheet / compare sets… (the Batch tab) pairs every revised sheet with its base sheet by shared text, aligns them and can Detect changes and Carry markups forward for all of them. Each pair ends as Done, Align manually, Failed or New sheet.

Ending

Review → End comparison closes the comparison. Saved comparisons stay listed in the revised file's Compare panel.

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