Revit Integrator - Export Error... The value for column 'B' in table 'Parameters' is DBNull

Tekla Structural Designer
Not version-specific
Tekla Structural Designer
Revit Integrator
British Standard
Not environment-specific

Problem Description

When exporting a model from Revit using the Integrator for Structural Designer the following Error occurs and no concrete beams or columns are exported.  Why does this happen and what is the solution?

Revit Error DBNull - 1.jpg

Error Message Text:

Error (System.Data.StrongTypingException): The value for column 'B' in table 'Parameters' is DBNull
Processing Object with RevitId = XXXXXXX


The standard Structural Families installed by Revit for concrete members with rectangular sections contain the dimension parameters b and h for the section breadth and depth respectively as shown in the picture below.  The Integrator for Structural Designer uses these parameters to set the section sizes for concrete members during the export.

The error will occur where custom families have been created by the Revit user for concrete members with rectangular sections which either omit or have different names for these parameters.  The error will occur during export as soon as the first member using one of these families is encountered.

Revit Error DBNull - 3.jpg


  1. Identify which Structural families are used in the model for rectangular section concrete members

  2. Open one of these for editing via the Project Browser as shown below

    Revit Error DBNull - 2.jpg
  3. Open the Family Types dialog (see picture above) then add the required Dimension parameters b and h for the section breadth and depth as shown below. If parameters for these with different names already exist, the Formula for the new parameters can be set equal to these.

    Revit Error DBNull - 4.jpg
  4. OK this then Load these changes into the Project via the Ribbon button for this as shown below:

    Revit Error DBNull - 5.jpg
  5. Then confirm the second option to update the model with this change.

    Revit Error DBNull - 6.jpg
  6. Repeat this process for all other in-use families with the same issue.

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