> For the complete documentation index, see [llms.txt](https://docs.openbrim.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.openbrim.org/templates/concrete-box-girder-bridge-workflow/export-cbg/dgn-additional-properties-cbg.md).

# DGN Additional Properties \[CBG]

For the definition of DGN Additional Properties to be meaningful, the file must be exported in the MicroStation (\*.dgn) format.

The Additional Properties section in a DGN file allows you to attach custom, user-defined information to DGN 3D elements when exported. This is especially useful in digital delivery projects, where adding metadata to objects is important.

**Objects:** This parameter specifies the 3D object or objects to which the Additional Property definition will be applied.\
To select the object or objects, click the three-dot button next to the Object parameter. In the interface that appears, click the Pick button, then choose the desired object or objects.

![image-20250929-221746.png](https://openbrim.atlassian.net/wiki/download/attachments/3290497056/image-20250929-221746.png?api=v2)

**Property Name:** This is the name of the attribute you want to define or attach.\
Examples include:\
\- Bridge ID\
\- Span ID\
\- Span Length\
\- Girder Length\
In other words, it defines what kind of information you are adding.

**DGN Value Type \[Text/Number]:** The data type of the property value, indicating whether the entry is stored as text or number. **Text Value:** The property's value when defined as text. **Number Value:** The property's value when defined as a numeric entry, often linked to calculations or measurements. You can either assign a parametric value or reference another cell in the project by using the Copy Reference action in the spreadsheet. The numeric value is always entered/stored in the internal unit system: inches for length and kips for force when using the imperial unit system.

![image-20250929-221307.png](https://openbrim.atlassian.net/wiki/download/attachments/3290497056/image-20250929-221307.png?api=v2)

![image-20250929-221319.png](https://openbrim.atlassian.net/wiki/download/attachments/3290497056/image-20250929-221319.png?api=v2)

![image-20250929-221354.png](https://openbrim.atlassian.net/wiki/download/attachments/3290497056/image-20250929-221354.png?api=v2)

**Unit of Measure \[L.F./S.F./C.F./C.Y./LB./TON/EACH/L.S./HR/EST./CALC/S.Y./ACRE/MI./GAL./CM/DAY/MGAL/MBM/UNIT/HUND/CRHR/PLS/DEGREE/STATION(ft)/STATION(US ft)]:** The unit associated with the numeric value, ensuring consistency in interpretation.

**Final Value (Read-Only):** Displays the numeric value expressed in the specified unit.


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