Wednesday, March 16, 2016

Extend Vertical Mullions to Add Anchor Points

In most curtain wall applications, the top of the vertical mullion reaches past the floor and is fixed to the structure at, or near, the floor using an anchor.



In some cases, however, the curtain wall height doesn’t reach to the floor above and a different anchoring strategy is required.  Often, this strategy includes extending the vertical beyond the top horizontal to create an additional anchoring point.


One solution is to create a Generic Object family and place it wherever the extension is required.  In this post, we will explain how to create an extended vertical in a Revit curtain wall object using mullion profiles and infill types.


 Start by creating a Revit Curtain Wall object.  The actual size doesn’t matter; the one shown here is 10’-0” long and 8’-6” tall and represents a wall that requires a 6½” mullion extension.  From the Architecture tab, add vertical and horizontal grid lines and make sure the top horizontal grid line is 8” from the top of the wall.




Click the Application button>New>Family and select Profile-Mullion.rft to open the mullion profile template.



Create a captured mullion profile as shown here.  The procedure for creating custom mullion profiles can be found on our site in this blog post.  Name and save the file then load the profile into the Revit project.




Edit the profile eliminating the glass pocket and pressure plate, Use the Save As option to save the profile with a different name then load it into the project as well.



In the curtain wall project, select all of the panels, select System Panel Glazed as the panel type, and then click the Edit Type option.



In the Type Properties dialog box, change the Offset value to -0.5” to shift the face-of-glass to the face of the curtain wall



Click Mullion from the Architecture tab then click the Edit Type button.  In the Type Properties dialog box, click the Duplicate button then enter a name for the new mullion.



In the Type Properties dialog, change the Profile to the first profile that you created in this exercise.



Place the mullions as show below, using the Grid Line Segment option from the Placement panel.




Click the Edit Type button for the mullion, duplicate it, and then change the profile to the profile that you created without the pressure plate.



Place the new mullions in the remaining, short grid line segments.  Select the top horizontal mullions then click the Make Continuous option in the Mullion panel.  Although this isn’t technically accurate regarding most curtain wall designs, it will prevent a void from being created, on the front of the system, where the pressure plate terminates when the horizontal butts against the vertical.  In the real world, the pressure plate extends past the edge of the vertical, while it does not in Revit.  Alternately, you could create custom horizontal geometry, to replace the profile-created geometry, which adheres closer to the physical representation.



Finally, select the top three glass elements and change their type to Empty System Panel.


That’s it!  The verticals now include extensions that will allow anchorage above the top of the exposed curtain wall and can be included in clash detection operations.


Images in response to Darren's comment in the Comments section below:

Flexible unit

Parameter driven values: