Shared parameters in Revit: the right way to structure a project file

What goes wrong

Every Revit project that involves more than one model author eventually runs into shared parameter chaos. One discipline creates a parameter called Fire_Rating. Another creates Fire Rating. A third uses FireRating. All three end up in the shared parameter file, none of them schedule-compatible, none of them exportable to the same COBie column.

This is a governance failure, not a Revit failure.

The structure we use

We maintain a single shared parameter file (BIMNovate_SharedParams.txt) per project — not per discipline. The file is hosted in the CDE and referenced by all Revit models in the appointment.

Parameters are organised into groups by discipline:

GROUP: BN_Architecture
GROUP: BN_Structure
GROUP: BN_HVAC
GROUP: BN_Plumbing
GROUP: BN_Electrical
GROUP: BN_Coordination
GROUP: BN_Handover

BN_Coordination parameters are added by the coordination manager and must not be modified by discipline authors. BN_Handover parameters map to COBie columns and are filled by the discipline responsible for the element type.

The naming convention

Parameters follow the pattern: [Discipline]_[Category]_[Name] where discipline is the two-letter code (AR, ST, HV, PL, EL, CO) and category is the element category the parameter applies to (Walls, Doors, Ducts, etc.).

Example: HV_Duct_InsulationThickness, AR_Wall_FireCompartment.

Shared across disciplines: CO_Element_ClashStatus, CO_Element_IssueID.

The workflow

1. The coordination manager creates the shared parameter file at project kick-off, seeded with the standard parameters from our office template.
2. Any new parameter request goes through the coordination manager — not directly into the file.
3. GUIDs are generated once and never changed. If a parameter is retired, it stays in the file (marked deprecated in the description field) rather than being deleted — deletion breaks schedules in other models that reference it.
4. The file is versioned in the CDE with a revision number in the filename: BIMNovate_SharedParams_R03.txt.

What this prevents

On a recent mixed-use tower (A+S+MEP, 6 models), this approach produced a schedule-ready Revit export on the first attempt — no duplicate parameters, no missing GUIDs, no COBie mapping errors. The coordination overhead was approximately 4 hours over a 10-month programme.

Compare that to the last project we inherited mid-stream with an unmanaged shared parameter file: 3 days of parameter cleanup before we could produce a usable schedule.