Updating the info regarding "Base Quantities with IFC export"

[davdelven]

Regarding this "already closed" thread from 2018 https://community.graphisoft.com/t5/Collaboration-with-other/Base-Quantities-with-IFC-export/m-p/257... , with a last comment by @stefan , I wanted to update the features from the IFC 4.0.2.1. schema version regarding IfcPile Base Quantities:

https://standards.buildingsmart.org/IFC/DEV/IFC4_2/FINAL/HTML/link/qto_pilebasequantities.htm

And this is how Graphisoft Archicad 28 uses IFC4 RV adding Base Quantities checkbox to publish a Pile

Operating system used: Windows 28.0.3. (3120) INT FULL

[Laszlo Nagy]

So, if I understand correctly, instead of exporting 8 IFC Base Quantities, as defined by the IFC 4 schema, Archicad exports only the "NetVolume" Base Quantity for Ifc Piles?

Question: how did you model the element? Using the Column tool/a Library Part/Morph tool/other?

Can you check if there are any differences when modeling it using the various options?

[davdelven]

Hi @Laszlo Nagy  

The tool choice creates different outputs, regardless the correct class mapping.

Here you have the three scenarios:

   

[Laszlo Nagy]

Thanks for the images. OK, no matter which tool is used, only the "NetVolume" is generated in the IFC file.

I will forward this to GS HQ.

[davdelven]

Thanks. 

Notice that there was also one without QTO_ and it was the Object tool.

[agroni]

Any news regarding this development?

In Archicad 28 the BaseQuantities for Footings are still only in NetVolume. The rest is missing.

[Laszlo Nagy]

I am wondering if this could be solved in some other way, specifically by IFC Property mapping, where you map the value of a library part (in case the element is modeled with a library part) or a Property to an IFC Property. Then, the desired value could be exported to the IFC file.

[agroni]

Our workaround is to create custom sets that contain those quantities. Thea are mapped from the tools geometry.

But I still did not find the option where you can map archicad quantitiy values into BaseQuantities. Archicad does this automatically.

[jonasm]

We use a similar workaround. I agree with your wish to allow for more custom mappings for BaseQuantites.

I feel that the current way BaseQuantities are created in Archicad kind of oppose a big strength of Archicad: Choosing the tool you want to get a desired result (2D and 3D) and then just classify it how you want. There are many cases where we model elements either with the wall tool or beam tool, according to the situation. We sometimes use beams for railings, the list goes on. But this creates the situation, that some of our Elements lose their BaseQuanities once we export to ifc. Not a big problem, as he have our custom Psets, but it's usually a bit of a discussion with some clients.

Building material is a similar topic, i would love to be able to change the building material name for ifc export, but this also seems to be impossible. So all our material names often including information only relevant to Archicad (e.g. "Insulation high priority") end in the ifc file.

[davdelven]

That should be a major issue when implementing IFC within the platform. What’s the point of setting up a mapping if you lose an essential layer of standardization in the process, specifically, the minimum set of quantities tied to what you’re semantically publishing?

Is there actually a wish for fixing this?

In the meantime, the software landscape is in the middle of a massive storm that’s going to change it forever.

We’ll see.