Schedule Filter Misses Shared-Parameter Data in Linked Models
A project team needs a door schedule that counts doors across the architectural model and a linked interior-design model. The architectural model has 180 doors; the linked model has 95 doors. The team added a shared parameter called "Fire Rating" to both models' door categories and populated it. The architectural door schedule shows 180 doors with fire ratings, but the linked model's doors do not appear. A team member tried to add the linked model to the schedule's view list, which Revit does not allow. Separately, the fire rating values in the linked model were entered as text ("20 min", "45 min", "60 min") while the architectural model uses a shared parameter of type "Text" with a lookup of "20 MIN", "45 MIN", "60 MIN". The code consultant requires a schedule that totals doors by rating across both models.
1. Explain why the linked model's doors cannot be added to the architectural door schedule, and propose the correct method to produce a combined count by fire rating.
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Revit schedules cannot include elements from linked models as schedule rows. A schedule is bound to the host model's elements; linking is a display and coordination mechanism, not a data-merge mechanism. That is why the team member's attempt to add the linked model to the schedule's view list failed, and why no amount of filter adjustment will make the 95 linked doors appear.
The correct methods, in order of preference:
- Schedule the linked model separately, then combine in a schedule key or a calculated table. Open the linked model (or a copy) and create its own door schedule filtered by Fire Rating. Export both schedules to a spreadsheet or use a schedule key in the host model to aggregate. This is the standard approach and preserves data integrity.
- Use a Schedule of Materials or a multi-category schedule in the host model only if the linked doors can be copied into the host - which they cannot without duplicating geometry. Not recommended.
- Use Ideate BIMLink or a similar data-exchange tool to pull both models' door data into one table. This is a software dependency and should be disclosed.
- For the code consultant's total, the deliverable is a combined count table, not necessarily a single Revit schedule. Produce the host schedule (180 doors) and the linked schedule (95 doors) and a summary table totalling 275 by rating. Document the method so the consultant can verify.
The judgment: do not fight the software. A schedule is a host-model object; the correct response is to produce the combined data outside a single schedule, with a clear audit trail, rather than to attempt a workaround that will silently drop doors.
2. Diagnose the data mismatch between the two models' Fire Rating values and recommend how to normalize them before the combined count is produced.
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The mismatch is case and format, and it will fragment the count if not normalized. The architectural model uses "20 MIN", "45 MIN", "60 MIN" (uppercase, with a space); the linked model uses "20 min", "45 min", "60 min" (lowercase). To a schedule filter, these are different strings, so a filter on "60 MIN" will miss every linked door entered as "60 min". The result would be a combined count that under-reports the 60-minute category and over-reports nothing, which is worse than an obvious error because it looks plausible.
Normalization steps:
- Decide the canonical format (uppercase, no space, e.g., "20MIN") and document it in the BIM execution plan.
- In the linked model, use a schedule with a calculated value or a bulk-edit tool to convert the text. A calculated value can strip spaces and uppercase, but it cannot write back to the parameter; use a schedule key or a data tool to write the normalized value.
- In the host model, verify the shared parameter's type and lookup match the canonical format. If the shared parameter is a lookup (a shared parameter file with a value list), the linked model must use the same shared parameter GUID, not a same-named local parameter. A same-named parameter with a different GUID is a different parameter and will not merge.
- Re-run the count and reconcile: 180 + 95 = 275 total. If the combined total is less than 275, doors are being dropped by a filter, not by a link limitation.
- Add a validation schedule that counts blanks and non-canonical values so future mismatches are caught before the consultant sees them.
The judgment: a schedule total is only as good as the parameter discipline behind it. Normalize the data, confirm the shared parameter GUIDs match, and reconcile the arithmetic before issuing.