# Properties for COBie

**URL:** <https://forums.buildingsmart.org/t/properties-for-cobie/2767>\
**Category:** Uncategorized\
**Tags:** ifc4\
**Created:** [June 12, 2020, 8:35am UTC](https://forums.buildingsmart.org/t/properties-for-cobie/2767 "2020-06-12T08:35:13Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![pilarjimenez](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.buildingsmart.org/pilarjimenez/32/407_2.png) [@pilarjimenez](https://forums.buildingsmart.org/u/pilarjimenez)\
**Post date:** [June 12, 2020, 8:35am UTC](https://forums.buildingsmart.org/t/properties-for-cobie/2767/1 "2020-06-12T08:35:13Z")

</div>

Hello everyone

My client has asked to get the COBie Excel (all information) from IFC4. I need to know which properties have to be completed during modelling. Is there any clear information about this?  
Thank you in advanced,

Pilar

---

<div class="post-metadata">

**Author:** ![Moult](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.buildingsmart.org/moult/32/196_2.png) [@Moult](https://forums.buildingsmart.org/u/Moult)\
**Post date:** [June 13, 2020, 9:47am UTC](https://forums.buildingsmart.org/t/properties-for-cobie/2767/2 "2020-06-13T09:47:37Z")

</div>

@pilarjimenez the official COBie 4.2 is in part 4.2 of the NBIMS document [here](https://www.nationalbimstandard.org/files/NBIMS-US_V3_4.2_COBie_Annex_A.pdf). In particular, see page 46 onwards which explains the IFC4 mapping.

However, I wouldn’t call it “clear”. It is written in human terms, not explicit code, so sometimes you will find ambiguity. You will also find that the spreadsheet representation of COBie (as opposed to the IFC MVD representation) is not a one-to-one mapping to IFC data. It is a many to one relationship. You can convert IFC to spreadsheet, but not the reverse. There is data loss.

I would also warn you that after reviewing this, you will find that many tools that claim to deliver COBie are actually doing it incorrectly.

Due to these faults in the design of the COBie mapping (i.e. the ambiguity), I have developed a [COBie IFC to spreadsheet converter](https://github.com/IfcOpenShell/IfcOpenShell/blob/v0.6.0/src/ifccobie/cobie.py). It will also output a log of errors it discovers in your IFC. It is part of IfcOpenShell and is 100% free and open source software. It is also fairly easy to read, so you can see for yourself _exactly_ how IFC gets translated into the spreadsheet.

Bill East has also got his own converter, but it isn’t quite so straightforward to use, as it requires quite a bit of prerequisite knowledge to run stand-alone, or somebody else to setup it in a BIMServer instance for you if you don’t know how.

---

<div class="post-metadata">

**Author:** ![pilarjimenez](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.buildingsmart.org/pilarjimenez/32/407_2.png) [@pilarjimenez](https://forums.buildingsmart.org/u/pilarjimenez)\
**Post date:** [June 14, 2020, 8:29am UTC](https://forums.buildingsmart.org/t/properties-for-cobie/2767/3 "2020-06-14T08:29:06Z")

</div>

Thank you Muda! Very usefull your comments. I’ve visited your link to your tool but i suppose it is not avaible yet. I only see code (i’m just an arquitect) but not an .exe or similar. Please, confirm me if i can test it.

Thank you again

---

<div class="post-metadata">

**Author:** ![Moult](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.buildingsmart.org/moult/32/196_2.png) [@Moult](https://forums.buildingsmart.org/u/Moult)\
**Post date:** [June 14, 2020, 10:17am UTC](https://forums.buildingsmart.org/t/properties-for-cobie/2767/4 "2020-06-14T10:17:13Z")

</div>

@pilarjimenez you can [download the free IFCCOBie tool from the BlenderBIM Add-on website](https://blenderbim.org/download.html).

Name your IFC file `input.ifc` and place it in the same folder as the tool, and run the exe. Please let me know if there are any issues!