Tip on Variable Wall Heights and Revit Groups

I meant to write a post about a one curious Revit -related issue that we had in-house that is related to Revit Groups and best practices on how efficiently handle unit types (condo unit / hotel unit layouts etc) with Revit.

So, we do a lot of hotels and multistory residential buildings. In schematics when we work on unit layouts (either hotel or condo units) we keep demising walls independent but we create a Revit Group for each unit type and we put in it interior unit partitions, doors, plumbing fixtures etc. It works really well because once a unit groups are being developed you can just populate the rest of the building with them. Then make adjustments to one instance of a group will update the rest of the instances. That works nicely when you have the same floor-to-floor on the levels that you populate these groups on but not so much when you want to stick the same unit on a level where floor-to-floor is different.

The problem is with the walls’ top constraint – if the walls in groups are constrained to a level on a top then when you place instances of the same group in places with different floor-to-floor Revit doesn’t know what to do with the wall heights (they have to be the same in all group instances therefore Revit throws you an error).

What we decided to do to simplify things and not to have to create a new group for the same unit with a different floor-to-floor we just kept walls in groups as “Unconnected” with explicit height setting – which works well until you cut a section.
Long story short – my colleague Juan Alvarenga suggested a solution. It appears that you cannot differ wall height from one Revit group instance to another but you can actually use “Attach Top” to attach a wall to a slab or ceiling in one of the group instances (if they are “Unconnected”) on a grouped wall and Revit will allow that! See image below. Problem solved…