In this case you can use the cut geometry tool to cause the void to cut solids that are created after the void.
Revit cut roof geometry.
Click modify tab geometry panel cut drop down cut geometry.
To enable this open the revit family with unattached voids and click create tab properties panel family category and parameters.
In the family category and parameters dialog select cut with voids when loaded and click ok.
On a small scale side when cutting geometry the application expects faces and edges to be accurately aligned.
Click modify tab geometry panel cut drop down cut geometry.
Simply select the cut geometry tool then select the floor element first and then select the family second.
Slight inaccuracies in the alignment may result in geometry that is invalid causing the cut command to fail.
When you create a void it affects only existing geometry.
Select the object to be cut.
Cut geometry with the cut geometry tool you can pick and choose which geometry gets cut and which does not regardless of when you created the geometry.
Then from the modify tab on your ribbon use the join geometry command and select the 7 1 2 roof and the wall.
When you create.
It will join in the wrong order and you will need to use the drop down menu next to join to switch the join order.
Load the family into the project and place it.
Please note that this cutting of the geometry was only possible because we checked the parameter cut with void when loaded.
That s more like it.
Load the family into the project and place it.
Open the revit family with unattached voids and click create tab properties panel family category and parameters.
Another small scale requirement is that geometry cannot be less than approximately 1 32 0 79 mm.
In the family category and parameters dialog select cut with voids when loaded and click ok.