December 24, 2014

Posted on December 24, 2014 by Bill Knittle, Synergis Building Solutions Engineer:
(Continued from Post “Back to Basics with Revit Walls: Part 1”)
In some cases, it is necessary to embed walls within walls to accurately represent feasible constructions. The difficulty in this is that Revit does not like overlapping walls. In this post will look at how to make this limitation work by cutting and joining walls together to resolve typical situations.
In the example below, you will notice that the exterior wall continues into the interior of the building model. Simply splitting the wall and swapping out the Wall Type will not yield a realistic result.
However, a new wall can be created in line with the exterior wall to generate the desired effect. The problem is that Revit will prompt you with a Warning dialog indicating the two walls overlapping. Thank you Captain Obvious!
Within the warning though, is a solution which recommended that one wall be cut from the other to resolve this issue. By going to the Modify tab, the menu for the Cut command on the Geometry panel can be expanded to reveal several options. In the example below, a partition wall was drawn in-line with the exterior wall in the specific location it needs to occur. The exterior wall is the wall to be cut by the interior partition. Therefore, the Cut Geometry tool should be used to select the exterior wall first and the interior partition second. The result is close but, not close enough.
The end result will still require additional attention to clean up the intersections. In the case of this example, the exterior walls were created with their Location Line being justified to the Wall Centerline while the interior partition wall was created using Finish Face Interior. Where the endpoints converge is dictating the current cleanup results.
Moving the Location Line of the walls can bring the desired results closer. Note that setting the exterior wall’s Location Line to Finish Face Interior and the partition wall’s to Finish Face Exterior is getting us closer. Then, the end grip of the selected vertical exterior wall grip can be pulled to south face of the interior partition wall.
To finalize the cleanup, we’ll resort to using the Join Geometry command to join the vertical exterior wall to the horizontal exterior wall. The Join tool is located on the same panel as the Cut tool. Dropping down the menu provides several additional options. Once Join Geometry is selected, choose the vertical exterior wall first and the horizontal exterior wall second. The wall cleanup will resolve itself. This process can be replicated on the opposite corner too.
Now, only one remaining issue needs to be resolved. The interior double-door is floating. This is because it is still hosted by the exterior wall. When the interior door is selected, the ribbon provides an option called Pick Primary Host. Selecting the interior partition wall will now resolve this issue.
Further adaptations can now be made to the interior partition that can realistically represent the preferred construction method. For instance, what if the interior partition wall needs to follow the slope of a roof over this small vestibule? Editing the interior wall’s profile becomes the best choice for this.
Because the interior partition is set to cut the exterior wall, the exterior wall will adhere to the new profile of the interior partition.
As you can see, the model is beginning to truly represent the preferred results. Embedding walls within walls using the Cut and Join Geometry tools can yield more desirable results. It should be noted that Curtain Walls contain a parameter to automatically embed the current wall into the wall it overlaps.
Whether you’re using Curtain Walls within Basic Walls or Basic Walls within other Basic Walls you should be able to mold the model to fit your design intent using Cut and Join Geometry. In the next exercise, we’ll bring the first two parts together and use them to resolve a very typical construction issue.