Find and list and locate Duplicate objects in model


i have been using the BIM interoperability tools to find create model health checks across the projects in the office. I have found that he duplicate objects card in power bi shows that there are a lot more duplicates than the Ideate explorer plug in can find.

I would like to create a script that helps me find the object names, locations and save it into an excel.

Many thanks,

What have you tried so far?

What version of Dynamo are you using? You might want to take a look at the new warning nodes in Dynamo which are there since Revit 2021 (I believe)

Hi ! to be honest i am not sure how to even start.
I could try to select all items in the project, then somehow retrieve their location?
then find all the items that have identical locations and list them into excel.
Or maybe i can find the duplicates in excel instead?

this is my current dynamo build i am using.

Oh cool! These warnings nodes are useful for other things so thank you for these.
The issue is that the project warnings don’t state that there are any duplicates in the project.

which has brought me here in the first place.

Any advice on where to begin would be a great start!
many thanks for your comment

How many duplicate objects are there. Because it might be possible that warnings such as:

Highlighted Walls overlap
Highlighted Floors overlap
Highlighted Lines overlap

Can cause duplicates.

I think it is also possible to extract the faulty element ids using BIM interoperability tools. Which gives you the ids of the elements causing the error. you can then use these ids incombination with Dynamo to find the faulty elements and their location.

So you can do 2 things:
check if BIM interoperability tools counts Overlaps also as duplicates, if so, you can use the Warning nodes as mentioned before

or extract the Element ids using BIM interoperability tools for the duplicate elements and retrieve them using Dynamo.

now you have somewhere to start, because I doubt there will be someone who is willing to write this all for you.

BIM Interoprability Tools uses the warning list in Revit to report back duplicates.

To find an remove duplicates there are several good posts on the forum - some which will even do the job in other ways as have been described. So there likely isn’t a need to reinvent the wheel in this case. :slight_smile:

This thread has some good samples: Delete duplicated elements - #5 by bruce.buckland
You’ll have to update to a newer version, but it should get you what you’re after. In particular this post from @chuongpqvn works well (chrome can translate the language for you):


thanks for you help. i was not asking for someone to write it for me… just some help

thank you @JacobSmall i will review both of these! There are 23,000 duplicates!

i thought they were using the warnings but the warnings here do not match the output.

So what is the warning criteria here?

my question exactly! What is included in this, if the warnings do not show 23,000 elements as duplicates. I have ran the MC a few times and it still comes up with the same, 23k duplicates. I wonder if design options has anything to do with it. but i feel that ideate would show this also.

That is why i want to make the script to find out exactly what these duplicate elements are.

Let me loop in a few people. :slight_smile:

From the makers of the tool:

The Duplicate Element check in the Dashboard checkset is supposed to do the following:

  • Collect every placed instance in the model
  • Remove any view-specific element (this should take out annotative elements)
  • Removes Truss category elements – we discovered they behave oddly when moved
  • Flags any two elements that have the same placement point or start/end points for line-based elements

I looked over the post and this check does NOT filter out for Options. The Best Practices check does, but it simply removes elements that are in options, which also may not have the desired outcome, but on the other side of things. If desired, the user certainly could add that filter to a copy of the Dashboard check and start using that one.

I will note that this check is more of a sledge hammer as opposed to a scalpel. Most of the Dashboard checks are intended to paint things with a broad brush to get a general feel of the model health. Users can always make their own checksets and Power BI dashboards to get a more refined look.

FWIW the idea that objects with the same placement point means duplicate items isn’t valid in my opinion. If you have a desk family with an insertion point at the middle of the back side and place two desks back to back you would have a ‘duplicate’ showing from this check, but a reasonable person would know it’s a non-issue. Same thing with a 5 unit high wall and a wall which starts at 5 units, but both have their location drawn on the level… I recommend building your own check set to get a refined look which has meaning to you (ie: pull the duplicate elements warning from Revit, which takes into account more than just insertion point).

For future questions on this tool, reach out to the BIM Interoperability Tools team directly at

this is great thank you!

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