1 Input

In this example, we are selecting the face of the wall to create a void, the void created will cut all the protruding walls.   The face you select can in practice be all types of surfaces and all kinds of voids can be made.  Number -5000 is the thickness of the void, you want it to be larger than the object you are going to cut.  The last input, Boolean is set to false since we don’t want the surface to thicken in both directions. 

2. Surface thicken

Based on the input value, the surface will thicken in the selected direction.  If you want to change the direction if the thickening, chance sign in front of the number.

3.Revit

Here we have taken the liberty to use a costume node ꟿ FamilyInstance.ByGeometry, Found in the package spring nodes, created by Dimitar.ven. the node import geometry to Revit as a void.