BIMIO Clash

Goal. Define which categories are checked against each other, with which engine, tolerance and severity criterion.

1. Click + Rule on the toolbar.The Edit clash rule modal editor opens with a new rule (Model ↔ Model comparison and Precise engine by default).

   

   assets/shots/clash/fig-03.pngFreshly opened rule editor, with the Comparison, Categories, Engine & tolerance and Severity cards visible

2. Type a descriptive name in Rule name and, if you wish, click the colour swatch to choose the rule's identifying colour.The colour only identifies the rule in the list; it does not affect the colour of the spheres, which always follows severity.
3. Under Comparison choose Model ↔ Model, Model ↔ Link or Link ↔ Link.The editor automatically adjusts the scope of each side: with Model ↔ Link, side A is set to the host and side B to links.
4. In Side A tick the categories to check. Use the search box to filter, Select all to tick everything visible and Only selected to review what is ticked.The list only offers categories with elements actually modelled in the chosen source (host or links), so there is no noise from empty categories.

   

   assets/shots/clash/fig-04.pngSide A panel with several categories ticked and the search box filtering

5. Repeat for Side B. If the side points to Links, tick the links to include under Links to include; if you tick none, all links are checked.
6. Under Engine & tolerance choose Fast (BBox) or Precise, and set the clearance tolerance in mm (0 = hard clashes only).With a tolerance greater than 0 and Precise mode, the rule also detects near-misses within that margin, which are classified as Clearance.
7. Under Severity choose Auto by penetration and adjust the thresholds (by default Critical ≥ 50 mm and Major ≥ 10 mm), or choose Fixed so all the rule's clashes get the same severity.The preview bar shows live how the Clearance / Minor / Major / Critical bands look with your thresholds.

   

   assets/shots/clash/fig-05.pngSeverity card with the coloured band preview

8. Click Save rule.The rule appears in the list and is saved inside the project (it survives closing Revit).

• Double-clicking a rule in the list also opens the editor.
• Start with a few categories per rule: it is easier to review than one giant everything-against-everything rule.

Goal. Detect the clashes and see the balance by severity.

1. Tick the checkbox of the rules you want to run (the header checkbox ticks or unticks them all).The header subtitle shows how many are selected.
2. Click Run selected. To run a single rule, click its play button in the Actions column.The run happens inside Revit; on large models with Precise mode it can take a while.
3. Look at each rule's result chips: counts in red (Critical), orange (Major), yellow (Minor) and green (Clearance), plus the resolved note if there are any.The status bar summarises: rules run, new clashes, resolved and total spheres in the model.

   

   assets/shots/clash/fig-06.pngRule list after a run, with severity count chips and the status bar showing the summary

4. Go to the model: each clash is now a coloured sphere at the exact point of the interference.The spheres are visible in any view and carry a summary in their Comments parameter, so you can set up a Generic Models schedule to list them.

   

   assets/shots/clash/fig-07.pngRevit 3D view with several red, orange and yellow spheres marking clashes

• Re-running does not duplicate spheres: each clash has a unique fingerprint and the existing sphere is reused.
• When you reopen the window in another session, the counts reload by reading the spheres already in the model.

Goal. Review clash by clash, navigating the model with automatic zoom and isolation.

1. Click the vertical BROWSE tab on the right edge of the window.The window widens and the navigation panel appears with the clashes of the highlighted rule (or the first one in the list).

   

   assets/shots/clash/fig-08.pngWindow with the browser open on the right showing the grouped clash list

2. Click another rule in the list to switch the browser's content to its clashes.
3. Filter with the chips (All, Critical, Major, Minor, Reviewed, Resolved, Ignored) or type in the search box to filter by element id, category, family or type.
4. Click a clash: Revit selects the elements, zooms to them and, if the Isolate toggle is on, temporarily isolates them together with their sphere.When you turn Isolate off or close the browser, the view is restored automatically.

   

   assets/shots/clash/fig-09.pngRevit with the two clashing elements isolated and the coloured sphere between them

5. Move forwards and backwards with the ‹ › buttons or with the Down/Up keys (also J/K).Navigation walks through the clashes visible under the current filters and wraps around when it reaches the end.
6. Use By: A / By: B to group by the element on one side or the other, and Group/Flatten to switch between the grouped and flat lists.Groups are sorted from most to fewest clashes; each group header shows the grouping element and its counts by severity, and folds or unfolds with a click.

• Grouping by side A or B is very useful for finding the main culprit: the beam or duct that racks up dozens of clashes.
• If both elements of a clash are in links (they cannot be selected from the host), Clash frames the marker sphere, which sits exactly at the centre of the clash.

Goal. Mark each clash as reviewed or accepted and correct its severity by hand.

1. In the browser, click a clash to select it and unfold its action row.

   

   assets/shots/clash/fig-10.pngSelected clash row with the four severity dots and the Review and Ignore buttons visible

2. To reclassify the severity, click one of the four coloured dots (red Critical, orange Major, yellow Minor, green Clearance).The sphere is recoloured instantly and that manual classification is respected in future runs: the automatic calculation no longer overwrites it.
3. Click Review to mark it as reviewed and confirmed (blue dot): it remains a live clash pending action.You can undo it with Un-review.
4. Click Ignore to accept the clash (for example, an overlap that is by design).It is suppressed: it does not count in the chips and will not reappear on refresh, not even in future sessions, because the status is saved in the sphere inside the model.
5. To recover an ignored clash, filter by the Ignored chip and click Restore.

• Ignored clashes are excluded from the BCF (they are accepted decisions, not issues) but do appear in the CSV with their status, for traceability.

Goal. After fixing the model, find out which clashes have been resolved and which persist or are new.

1. Fix the model in Revit with the Clash window open (it is modeless).
2. Click Refresh.The ticked rules are re-run; if none are ticked, all enabled rules run. The category and link index is also rebuilt so the editor reflects the current modelling.
3. Check the result: clashes that no longer exist move to Resolved and their sphere turns translucent grey; new ones appear with a coloured sphere; persisting ones remain (keeping your manual severity and the Reviewed status).If an element moved, its sphere is repositioned at the clash's new centre.

   

   assets/shots/clash/fig-11.pngModel with a mix of grey (resolved) and coloured (active) spheres after a Refresh

4. When the grey spheres no longer add value, click Clear spheres to delete all spheres from the model and start from scratch on the next run.Clear spheres deletes all spheres, including resolved and ignored ones, without asking for confirmation. Because the Ignored status lives in the spheres, those clashes may reappear when running in a future session; while the current window remains open, ignored clashes are remembered in memory and do not come back.

• Refresh regularly (for example, before each coordination meeting): every run adds a point to the report's burn-down curve.

Goal. Check the current selection without creating any rule.

1. In Revit, select the elements you want to check (at least 1 to check against the model, at least 2 to check among themselves).If the selection does not reach that minimum, the check ends without doing anything (no error is shown).
2. Click Quick Clash on the toolbar.
3. In the dialog, choose Vs whole model (the selection against the entire model) or Among selection (only among the selected elements).The check always runs in Precise mode, with no clearance.

   

   assets/shots/clash/fig-12.pngQuick Clash dialog with the two buttons Vs whole model and Among selection

4. Review the results: spheres appear in the model and an informational Quick Clash row appears in the list with its counts.Quick Clash results are browsed, classified and cleared just like those of any rule.

• It is ideal for self-checking before synchronising: select what you have just modelled and run it against the model.

Goal. Distribute the clashes across the team with an owner, urgency, comment and deadline.

1. First configure the assignment parameters: open Settings (gear), in the Parameters section choose which project parameter corresponds to Assignee, Urgency, Comment, Detected and Due date, and click Save parameter choices.The drop-downs offer the project's text-type, instance, editable parameters. They must exist in the project and apply to the spheres (Generic Models); Clash does not create them.

   

   assets/shots/clash/fig-13.pngSettings panel open with the seven parameter drop-downs

2. In the browser, highlight the clashes to assign: click for one, Ctrl+click to add or remove, Shift+click for a range.When you highlight rows, the blue assignment bar appears with the title Assign N clashes.

   

   assets/shots/clash/fig-14.pngBrowser with several rows highlighted and the assignment bar unfolded

3. Fill in whichever fields you want: Assignee (with suggestions from the current user and owners already recorded), Urgency (Critical, High, Medium or Low), Comment and Due date (for example 2026-07-15).Fields you leave empty are not touched on the spheres: you can change only the urgency without overwriting the owner.
4. Click Apply to selection.The values are written to the parameters of the selected spheres and the status bar confirms how many were updated. If none of the chosen parameters exist on the spheres, a warning tells you so you can configure them.
5. Synchronise with the central model so the team can see the assignments.Anyone can look them up in a Generic Models schedule filtered by those parameters, with no need for BIMIO.

• The Detected parameter is filled in automatically with the detection date the first time the sphere is created, if you have configured it.
• Use Clear selection to undo the highlighting without applying anything.

Goal. Stamp onto the elements themselves which ids clash with them and how many clashes they accumulate, for filters and schedules.

1. In Settings (gear), choose the Clash IDs and/or Clash count parameters and save.You need at least one of the two configured; if not, Write params will remind you.
2. Click Write params on the toolbar.
3. Confirm the warning.The operation writes to the model's elements and those changes synchronise with the central model; that is why it asks for confirmation.
4. Check the result: every host element involved in active clashes receives the list of ids it clashes with and its clash count; each sphere also receives its own data.The write is reconciling: elements that no longer clash but kept an old count are cleaned up (count set to 0 and ids emptied), so no stale data remains.

   

   assets/shots/clash/fig-15.pngProperties palette of an element with the clash parameters filled in (ids and count)

• Only host model elements are written: link elements are read-only from the current project.

Goal. Share the coordination status with people who do not open Revit, or take the clashes into another tool.

1. Run at least one rule (with no recorded clashes there is nothing to export).
2. Click the HTML button on the toolbar.
3. In the save dialog, choose the format in the type drop-down: HTML report (.html), CSV for Excel / Power BI (.csv) or BCF 2.1 for coordination (.bcfzip), and click Save.

   

   assets/shots/clash/fig-16.pngSave dialog with the three formats available in the type drop-down

4. Review the result. HTML: a self-contained report with KPIs, a coordination health score, a severity donut, a burn-down curve across runs, a per-rule ranking, a discipline matrix, the most conflicting elements and a filterable table of all clashes; it works offline and has light/dark mode. CSV: one row per clash with rule, severity, status, both elements with category, family and type, penetration, coordinates and dates; it opens in Excel with accents displayed correctly. BCF: one topic per clash with a viewpoint on the clash centre and the two elements referenced by their IFC GUID, ready for BIMcollab, Solibri, Navisworks or Revizto.The HTML and CSV open automatically when finished; the BCF is shown selected in File Explorer.

   

   assets/shots/clash/fig-17.pngClash HTML report open in the browser with the severity donut and the burn-down curve

• When you re-export the BCF, each clash keeps the same topic GUID, so the coordination tool can track it across versions.
• The BCF excludes ignored clashes; the CSV includes them with their status.

Goal. Reuse the practice's check matrix in any project.

1. Click the export button (up arrow) and save the clash-rules.json file.The file includes a self-explanatory _README block with the format of each field, designed so a person (or an AI) can edit or create rules directly in the JSON.
2. In the other project, open Clash and click the import button (down arrow); choose the .json.
3. Confirm the message with the number of imported rules.Imported rules are added to the existing ones with new ids and numbers, so they never collide with the ones you already had.
4. Review any imported rules that point to links: links are referenced by the source project's identifier, so in the destination project you should open each rule and tick the links again (with none ticked, all links are checked).

• Importing always adds, never replaces or deletes: if you import the same file twice you will end up with duplicate rules.