"Fix Groups..." - "different base heights relative to the group origin", strange issue.

[B4-DavidG]

Hi everyone!

We have a multifamily building where we have units as groups placed on different levels. When there's an update for a unit, we just reload the unit file as a group and it gets updated everywhere. This is what we usually do.

This time we have an issue which I don't even know how to explain. We have a group of walls that throws Fix Group errors when placed on higher levels. Weird thing is that some walls are fine, some give errors. All of the walls have same constrain conditions - Top unconstrained, not attached.

I'm adding a project file so you can have a look. Maybe find the culprit of the issue. It's in 2022.1.1

[dtiemeyer]

I've recently gotten same error with MEP elements, even if those elements were hosted to reference planes included in the group. Definitely something strange happening with Groups pasting to different levels. Following this thread.

[RDAOU · Accepted solution]

@B4-DavidG 

Change/Move the group origin to mid height of the wall...see GIF below

[B4-DavidG]

Thank you so much for this. At least we have a workaround.

Can you explain what is happening? This can't be intended design of Revit. Could this be a bug?

We religiously tried to keep model origin at z=0 thinking it might be causing the issue.

And why is it happening with some walls but not with others?

[RDAOU]

@B4-DavidG 

I am not sure what you mean...What does the Group origin has to do with Model Origin and the 0 elevation?  The group origin is one of the factors which define the behavior of the grouped components in relation the surrounding elements outside the group. It can be at any elevation it needs to be... Otherwise they would not give you the open to relocate it and they would simply make is plane based and fix it at 0 elevation!!!

As far as I know there is no bug. You only shared the group and not the context it is being used in. If you want an explanation of what exactly is going on you need to share the model ... till then it shall be the solution you referred to as a Workaround : o)  

[B4-DavidG]

Perhaps I didn't explain properly. Unfortunately our company policy doesn't allow me to share the full project file. But I shared the project file with irregular model group behavior which is exactly the same thing.

We've used this approach for couple of project before. We never had to move the model group origin to the middle. The issue is specifically for those walls in the group. You can test this yourself. Create new wall group in an empty file, import in the project I shared above and try to populate it. All without having to move the group origin Z coordinate. You won't have any problem doing that. What I don't get is, why are those specific walls acting differently.

Hope I made myself clear.

[RDAOU]

@B4-DavidG 

Please Revit previous reply and read again...the .RVT you posted is fine. The issue is with the Walls Grouped and the relationship/properties they inherited from the original project you initially created them and the group in.

• With those walls and the GROUP you created your solution is to Move the origin of the Group UP 
• If you want to keep the Origin @ Level 0; you need to recreate the group using Walls which have no constraint/relation to ABSOLUTELY NOTHING outside the group

See GIF below as well as Your .RVT used/Revised ...

I used Dynamo to Recreate your walls with the same Layers and Layer function then grouped those in the same configuration, IN the project you posted (Origin at 0' and the group works perfectly fine)

[B4-DavidG]

Thank you for your time trying to explain this. Please don't get annoyed when I have additional questions. I'm just trying to understand. I'm not a newbie with Revit either, I know what I'm doing.

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@RDAOU wrote:

• With those walls and the GROUP you created your solution is to Move the origin of the Group UP 
• If you want to keep the Origin @ Level 0; you need to recreate the group using Walls which have no constraint/relation to ABSOLUTELY NOTHING outside the group

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In my original post I clarified that none of the walls have any constrains - except for base level, obviously. No hosted families, details or other elements. I literally created orthogonal wall in the middle of the room, connected to nothing.

I tried manually redrawing walls in an empty file and creating a fresh group, only using the same wall types (by copying the wall over) but I had the same error. Even in the test file that I shared, if you select one of the "problematic" wall types and group it, you'll get the same error. Dynamo recreated the walls from scratch and I'm guessing that helped.

I'm sure you can see how that doesn't make any sense, except for my wall types being "corrupted" in some way, which sounds like a bug to me.

Anyway, I'm forever grateful for the solution that you provided. Selecting your post as such.

Thanks!

[RDAOU]

@B4-DavidG 

The only thing I can say is that if it is a bug, it would affect all walls in the model. Not just the walls which were copied from somewhere (Considering that the file you attached was not the original model they were created in). Lots of times users create an element and assume that it has no relation to any other element or no constrained when in-fact Revit build such relationships in the background (for year users complained about that). Why it does that? : o) you will have to ask Autodesk 

Anyways, should you not like the elevated origin...use the previously attached file >> rename the walls similar to the ones in your main model >> save the group as a .rvt >> load into your model and overwrite wall types with the new (I think it will fix)

Or maybe try transferring project standards (only walls) from one project where you had no issues to the current one