Groups - Change instance parameters of groups based on level

This is an odd question but would be a big help. We work on muli-family housing projects. Our process is to get a floor plan for the units and make that into a group. Then we multiply that group across the project. This way if the developer makes a change we can change all of them at once.

Now the issue is that we have different floor to floor heights. So we are trying to find a way to simply change the wall heights in the group based on the levels floor to floor height. That is the only element in the group we want to change into a parametric element.

I have been exploring but have not found a viable route. Any suggestions or advice?


As far as I know, you can’t use a parameter to control the height, nor can you associate these to the ‘level above’ even though they’ll know what’s above them. What you CAN do is attach them to the slab on the level above using the “attach top” tool.

You might be able to expedite to some extent, but automating the “attach to” part isn’t possible as it hasn’t been exposed in the API as far as I can tell. While it is possible to select the all walls in each group by level via Dynamo, my initial attempts at this brought me to the ‘modify multi type selection’ toolset rather than the ‘modify wall’ toolset so "attach top’ wasn’t available. Sending element IDs to the clipboard and selecting by ID might allow for this type of workflow.

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Thanks. Yes this is the dead end that I came across as well. Theoretically this should not be possible, but if it were, we would save tons of time. Will keep digging…

What is the point then of having groups in Revit? Not only they never behave as they should, but they are also useless. Can Autodesk stop adding more useless features and fix the ones that really need to be fixed, and can be actually useful to the majority of users?

Sounds like an issue for the Revit forum.

Groups do in fact behave as they are intended, but you desire they behave differently. A well worded post on the Revit Ideas station would be the best way to get some attention on this, rather then discussing it int he Dynamo forum. Be sure to make a strong business case, meaning you need something beyond “they dont’ behave as they should.” Highlight why the change is important to the industry, not just your current office/situation. I can confirm that all ideas with 50+ votes are reviewed, and while they’d like to implement a LOT more then they do, there are limited resources and implications of some changes which would actually do more harm then good if instantly rolled out, so sometimes it takes a few releases before the software gets to where it really wants to be.