MULLION LENGTH PARAMETER TO SCHEDULE

[Robert6N3TH]

It is simple, since mullions, already have a length parameter in their properties. 

It should be simple to allow Revit to pull that length into a multi-family schedule.

I have seen some work arounds with using Dynamo and Shared Parameters.

[kh_jea]

Currently you cannot schedule the constraint parameters, dimensions or material of a mullion.

As a result one is forced to add extra parameters to schedule the necessary information. But these (shared) project parameters aren't intelligent, e.g. if I add a Width parameter it will not respond to changes in "Width on side 1" and "Width on side 2".

Allow for scheduling of all parameters of a curtain wall mullion.

This seems like such a basic thing to have available in Revit.

[Basam.Yousif]

Is this what you mean?

Mullion schedules work, but not Multi-Category Schedules?

[julia_lubacheskiQ3DPX]

Hi Robert,

You’re absolutely right — each mullion in Revit does have a Length property, but unfortunately, this value isn’t exposed as a schedulable parameter in native Revit. The parameter exists internally, but it’s considered a system-calculated value, not a true instance or type parameter, so it can’t be directly pulled into a curtain wall schedule.

That said, there are a few reliable workarounds:

1. Dynamo workflow (most common):
   You can use Dynamo to extract each mullion’s length from its geometry and then write that value into a shared instance parameter. Once the data is stored in a shared parameter, it becomes available for scheduling just like any other field.

   • Input: Curtain Wall or Curtain System

   • Node: FamilyInstance.Location → extract curve → Curve.Length

   • Output: Write to a shared parameter called “Mullion Length”

2. Tag workaround (visual only):
   If your goal is just to display the length in drawings, you can create a Tag family with a calculated value, though this won’t populate a schedule — it’s purely for annotation.

3. Manual or API approach:
   For automation at scale, you could also use the Revit API (or a custom add-in) to read the LocationCurve.Length property and push that into a shared parameter automatically.

So yes — you’re correct that the parameter already exists internally, but until Autodesk exposes it as schedulable, the Dynamo + Shared Parameter route is the most practical solution for production workflows.