One of the main issues with groups is their need to be "exactly the same" for all instances. But what if we could create a parameter on a group that we explicitly tell Revit it can vary. Yes we have the "Vary by Instance" for individual element parameters when grouped, but this doesn't help with geometry...
For example:
I have a typical amenities layout group in my floor plan. The layout is the same for all levels, however, my floor to floor height happens to vary on some levels. Currently this requires me to either:
- Use the tallest, and have Walls overlap between levels, when they vary
- Use the smallest, and have a gap on some levels.
- Create a new group and now I have to manage duplication of the layouts, to keep them consistent.
All these solutions suck.
What if we were able to add some Reference Planes to the Group (for top and bottom) and constrain the top/bottom of the walls to these Reference Planes. Then I could add an Instance Parameter to the Group for "Wall Height". This then allows Revit to understand when you really want something to vary between group. Similarly for wall end conditions, you could create length parameters to control those scenarios. Or simply set an "Unconnected Height" for the walls, and link this parameter to a new instance parameter for the group. Essentially giving some "family" capabilities to groups...
This would provide a really powerful way of modelling parametrically and eliminating duplication and manual coordination.