# What is the actual status of IFC4ADD2TC1

**URL:** <https://forums.buildingsmart.org/t/what-is-the-actual-status-of-ifc4add2tc1/663>\
**Category:** Users\
**Created:** [November 19, 2018, 7:57pm UTC](https://forums.buildingsmart.org/t/what-is-the-actual-status-of-ifc4add2tc1/663 "2018-11-19T19:57:51Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Teun](https://avatars.discourse-cdn.com/v4/letter/t/5f8ce5/32.png) [@Teun](https://forums.buildingsmart.org/u/Teun)\
**Post date:** [November 19, 2018, 7:57pm UTC](https://forums.buildingsmart.org/t/what-is-the-actual-status-of-ifc4add2tc1/663/1 "2018-11-19T19:57:51Z")

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L.S.  
A friend pointed me to the documentation website of IFC4\_ADD2\_TC1 - 4.0.2.1 [Official]  
The site suggests that this is the latest and official version of IFC 4  
But on the BuildingSmart site I couldn’t find any link to TC1.  
There is not even a news update about this TC1 version.  
So can anybody tell me the actual status of this TC1 version?  
Teun.

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**Author:** ![jwouellette](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.buildingsmart.org/jwouellette/32/2140_2.png) [@jwouellette](https://forums.buildingsmart.org/u/jwouellette)\
**Post date:** [November 20, 2018, 4:42am UTC](https://forums.buildingsmart.org/t/what-is-the-actual-status-of-ifc4add2tc1/663/2 "2018-11-20T04:42:25Z")

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Hmmm, I believe the TC1 version is “official”, but I could be wrong. Let me check with the MSG. However, The “old” technical site is out of date. I am trying to remedy that right now. We’re in the middle of switching the long-standing [buildingsmart-tech.org](http://buildingsmart-tech.org) site to a new platform, layout, and domain. This will include all the latest links to the current documentation for **_all_** versions of IFC2x3 and IFC4. Check back in at 01 December…

We’ll also try to make sure we make announcements through the Forum to help orient everyone to the new versions and when they are officially available.

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**Author:** ![Teun](https://avatars.discourse-cdn.com/v4/letter/t/5f8ce5/32.png) [@Teun](https://forums.buildingsmart.org/u/Teun)\
**Post date:** [November 21, 2018, 7:48am UTC](https://forums.buildingsmart.org/t/what-is-the-actual-status-of-ifc4add2tc1/663/3 "2018-11-21T07:48:04Z")

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Thanks for the reply. So we are still not sure if it is offical.

In the mean time i will take a look what I should be changing in our basic mapping based on the changes in TC1. E.g. IfcWallElementedCase .www.buildingsmart-tech.org/ifc/IFC4/Add2TC1/html/schema/ifcsharedbldgelements/lexical/ifcwallelementedcase.htm (back) to a IfcWallType.ELEMENTEDWALL or something like that.

Do you know if there is a place where I can find the reason for this backwords changes.  
Because for a relative outsider of the actual discussion this doesn’t make sense. 😉

In our workflow we use some direct linking to the online documentation.  
e.g. IfcDoor \>\> .www.buildingsmart-tech.org/ifc/IFC4/Add2/html/schema/ifcsharedbldgelements/lexical/ifcdoor.htm or even .translate.google.com/translate?js=n&sl=auto&tl=nl&u=http://www.buildingsmart-tech.org/ifc/IFC4/Add2/html/schema/ifcsharedbldgelements/lexical/ifcdoor.htm (I cannot include a real link, but you get the idea)  
Based on the TC1 link I got, this stil works for us. So that is fine.

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**Author:** ![TLiebich](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.buildingsmart.org/tliebich/32/71_2.png) [@TLiebich](https://forums.buildingsmart.org/u/TLiebich)\
**Post date:** [November 22, 2018, 9:14am UTC](https://forums.buildingsmart.org/t/what-is-the-actual-status-of-ifc4add2tc1/663/4 "2018-11-22T09:14:01Z")

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IFC4 Add2 TC1 is official. It is both:

- the baseline for the official IFC4 Reference View certification process
- the baseline for ISO 16739-1:2018, the soon to be published update on ISO side

the main issue is with the websites, see answer by @jwouellette. Hope that this get fixed soon