Versions & Compare
Keep a version history of server-stored models and compare any two versions in tables and side-by-side 3D.
When a model is stored on the server, COREY keeps a numbered version history for it. Each new upload becomes the next version, and any two versions can be compared — element by element, field by field, and side by side in 3D.
This is how you answer questions like "what changed between the model we reviewed last week and the one submitted today?" and "did the resubmission actually fix the failed checks?"
Versions and compare need the optional self-hosted backend, because the versions live on the server. Local-only files don't have a version history — see Local Setup if your team hasn't set up storage yet.
Version history
Open the Files menu to see your server-stored models. Each model has a version history you can expand:
- Every version shows its number (v1, v2, …), an optional label, file size, upload date, and a change summary — how many elements were added, removed, or changed compared to the previous version.
- Download any version as an IFC file.
- Select versions with the checkboxes to delete old ones. A model always keeps at least one version — to remove the last one, delete the model itself.
Adding a new version
There are two ways to create a version:
- Upload new version in the model's version history — pick a newer IFC export of the same model, optionally with a label.
- Save as new version after an Excel round trip — instead of downloading the edited IFC, save it straight to the server as the next version. See Excel Round Trip.
Either way COREY computes the change summary automatically, so the history reads like a change log.
Comparing two versions
Open the compare dialog
In the Files menu, expand the model's version history and click Compare versions. (The button appears once the model has at least two versions.)
Pick base and target
Choose the Base (before) and Target (after) versions, then click Compare. Base is your reference point — usually the older version — and the results describe what the target did relative to it.
Read the differences
The results are grouped into three lists:
| Group | Meaning |
|---|---|
| Changed | Elements present in both versions whose data differs. Expand a row to see exactly which fields changed, with before and after values. |
| Added | Elements that exist only in the target version. |
| Removed | Elements that exist only in the base version. |
Elements are matched by their IFC GlobalId, so renames and reordering don't show up as false adds/removes.
Check the validation diff
If you have clauses configured, COREY re-runs them against both versions and shows how the results moved:
- Resolved failures — failing in the base, passing in the target. This is the list that tells you a resubmission worked.
- New failures — introduced by the target version.
- Still failing — unresolved in both.
With no clauses configured, the validation diff is skipped and you get the structural diff only.
Open the visual compare
Click Open the compared versions side by side in 3D to see both versions in two camera-synced viewports — orbit or zoom in one pane and the other follows.
Differences are color-coded consistently across the 3D view, the differences list, and the properties panel:
- 🟢 green — added elements
- 🔴 red — removed elements
- 🟠 orange — modified elements
Click a row in the Differences panel to focus that element in both panes, and use the Properties panel to see its changed fields highlighted in the same colors. Press Escape to close the overlay.
Good habits
- Upload resubmissions as new versions of the same model instead of creating a new model — that's what makes the change summary and compare possible.
- Use labels ("Tender issue", "Post-review fix") so versions are recognisable later.
- After an Excel round trip, save the result as a new version and compare it against the original to double-check exactly what your edits touched.
- Compare with your clauses configured whenever you can — "Resolved failures" is the fastest way to confirm a fix.