buildingSMART Forums

Cobie to IFC export issues.

I am using “IFC 2x3 CObie 2.4 Design Deliverable” to export to IFC from revit model.
The Revit model has been populated with COBie data by parameter mappings.

My problem is that the exported IFC does not have some COBie parameters which were mapped in Revit. like CObie Type name, COBie Component name …

Please find attached ,

Did you forget to attach a file?

Also, if anyone can respond to my issue about running COBie IFC outputs against the COBie MVDXML, that may help this issue. See this thread: COBie and IFC mapping

You have to build a new one with IfcDoc tool (RV and DTV)

Anything you see from spreadsheets to MVDXMLs are all based on IFC 2x3 and most of them don’t work or have some issues inherently

Also, in the near future, you have to think about “Granular Assets [1][2]” and your issues will increase

As I know Bill East and his team [John Ford] [Nick Nisbet @nn1] have developed a good solution but is private for commercial purpose

It may well be the case that I will look at rebuilding the COBie MVDXML, and making it available for IFC4. It would greatly benefit the community if this exists.

But first before doing this task, perhaps we can get someone else, perhaps @TLiebich or @jonm to reconfirm that the current COBie MVDXML is indeed, broken? Perhaps it is simply a problem with how I was attempting to load it.

Hi Dion,

We should certainly discuss this before you (and hopefully myself and others) progress this.

Cheers,

Jon

Aah i tried attaching file but since i am a new used , im restricted.

Thanks guys for your reply. Anyone who would want to look at the file please share your email , so that i can send you related files.
Thanks

Please send to dion@thinkmoult.com - I’d be happy to take a look.

My original issue is still not rectified. Any help !
I do not want to map the parameters again in IFC .

@shoiab.1618 as mentioned in my email, you have to export first to an IFC, and only then extract your COBie spreadsheet from that. Otherwise, there is little guarantee that your data is correct in the IFC, hence why you are finding data discrepancies between the quality of the IFC file and the data in the spreadsheet.

IFCs produced by Revit are, unfortunately, extremely poor in quality. The solutions and workarounds are not easy, but it is something you will face if you choose to work with Revit. You can read this article to help you improve your mappings properly in Revit to IFC:

https://thinkmoult.com/how-to-create-better-ifc-files-with-revit.html

However, a precursor to getting correct COBie data is to ensure that your data is actually classified properly. Otherwise, you will end up getting elements which are not meant for CAFM systems being exported, or elements that are meant to be exported will not be exported. You will need to audit every single element in your IFC file to ensure that it has the correct IFC class. You can use this tool to help you find the correct IFC class:

https://blenderbim.org/search-ifc-class.html

Finally, the IFC export you provided to me is an IFC2X3. The official MVD endorsed by Bill East is the COBie IFC4 MVD. I quote Bill East himself below. You will need to fix your Revit export to export an IFC4.

… the COBie MVD found http://docs.buildingsmartalliance.org/MVD_COBIE/ is actually NOT out of date. It is the on-line duplicate of the information found in the actual standard which is found at www.nationalbimstandard.org under Chapter 4.2. What is on buildingSMART intl. is NOT the COBie standard in any way shape or form – it an aggregation of things that my team funded over a decade ago that have not kept up with the time. While there may be movement to fix this within the next 12-18 months, that unfortunately does not help you figure out the wheat from the chaff today…

You may consider looking at BlenderBIM, which has tools to help audit IFC classes - but be forewarned that it is still alpha software.

Thanks for your valuable input.
I will have to do some research .

Anyways, thanks again for the post.