Behavior of Editable Wall Families (rfa)

[clog boy]

This is not a question, more of an answer that nobody asked for (but could still be very useful). We could turn it into a little knowledge base.

If you've been around the block a few times, you'll know how to make an rfa in the category of walls, floors or roofs (save a group that you made inside an in-place family of one of those categories). Because of the typical behavior of the Walls category, everything you create within that category will automatically join with everything else within this category when it overlaps. This has a large potential for many use cases.

What I stumbled upon by accident is that this is also true for invisible solids within an rfa in the Walls category. Normally, you'd have to make a wall-based family and create a void geometry/opening for it to automatically cut with a host wall. There are many valid reasons why hosted families are not practical within a big BIM. Turn the void into a Wall in an unhosted family and give it an invisible material: Boom. Same result. Revit doesn't even care if it's nested several levels deep. This way, you can make unhosted rfa families that join (or cut, when there's an invisibvle wall) with whatever wall it intersects, unless you manually unjoin it after the fact. The dummy wall could even export to IFC as its own individual entity.

What potential would you see for this behavior? Have you tried this before, and have you encountered any sort of glitch / stability issues?

EDIT: if more appropriate, would this be suitable for the Tips & Tricks section? Apologies for any inconvenience.