Weird face with retreiving mullion info


I’m trying to filter the subcategory mullions from the family in order to calculate their areas. I’m fine here.

But the problem is that dynamo makes a weird extra face when retreving the mullions from a project. So far I have no idea what caused this. I grabbed a window family from a Revit sample (rac_basic_sample_project) project where it works fine. But if I then use a basic family from Revit’s architectural template (M_Window-Casement-Double 1400 x 1800mm), I get a crazy face (see attachment).

Does anyone have an idea what could be causing this and how I can fix it.

Dynamo Core: 2.3.11775
Dynamo Core: 2.3.11830

Revit Version: 2020.2.6

Note: I tried to take everything within one picture(new user). Hopefully it is informational enough.

Hi @f.van.keulen

Are you trying to get only outer mullions?

Hi @Kulkul,

Sorry for my late response. But i am looking for all the mullions in the family. We want to get the whole area of them for calculations. I have no idea how to solve that!