No, it’s correct… The BIM workbench resides in /Mod/BIM, but the classification files must not go there, otherwise they’ll pollute the source code. So they go in /BIM (one level up). That’s where all the presets of the BIM wb get stored (currently only the project tool)
You are right! Sorry my mistake, I didn’t see that we were talking about 2 different locations 
As of 496df343, Arch & BIM workbenches now have a new “Reference” tool/object that can import/link the geometry of any object that has a shape (including BuildingParts) from another document. The linked document is scanned for changes every minute (that interval can be changed in the preferences) and if changed, the reference object is marked for recompute (no automatic merge, on purpose). In context menu, you have options to force reload or open the linked file.
This is a VERY simple implementation, it doesn’t open the linked file in FreeCAD, it just swallows the needed brep data from it. This is a quite different path than Assembly3, so I chose not to use it, at least for now. The idea here is not to have fine control over the linked objects, but rather be able to work with very large files (say, whole buildings or building levels).
In the future, I’ll try to add one more level to this, which is to store and import the inventor representation only. But this should already allow us to work with significantly larger models.
Please test! 
Very exciting! And I am having even much bigger hopes for the inventor representation 
I am a bit lost. Can you give a short tutorial to help us to run a test?
Hi. Thanks for the new features in the BIM WB.
One feedback: The new tutorial embedded in BIM WB does not show the images.
OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.15299 (Git)
Build type: Release
Branch: master
Hash: 5217b245b4f98cf1e3f63ecfe20e379fe4923d80
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: English/Australia (en_AU)
Thanks for the feedback! I’ll have a look at it. Definitely need to run FreeCAD on windows more often 
Works fine for me on Linux (Ubuntu).
OS: Ubuntu 16.04.5 LTS
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.15302 (Git)
Build type: Release
Branch: master
Hash: 2e03d2f298677b8212c22cbbc3cb20b7c80eabb5
Python version: 2.7.12
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/UnitedStates (en_US)
I just noticed that the CANCEL button of Bin Project Setup panel does not work in my case.
OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.15299 (Git)
Build type: Release
Branch: master
Hash: 5217b245b4f98cf1e3f63ecfe20e379fe4923d80
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: English/Australia (en_AU)
Fixed! Thanks for reporting
Another thing is the Arch Equipment tool is missing in the BIM WB toolbar
OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.15417 (Git)
Build type: Release
Branch: master
Hash: cc0ea5571e0bc451d415bd8624df0b3fa40f447b
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: English/Australia (en_AU)
Yes I removed it yesterday in favor of the Library button. I think the arch equipment button itself, its only purpose is to convert any shape object to an equipment bim object. Very little use to have such a prominent place. And in fact, now that any Arch object can have any IFC role, this tool makes even less sense… It actually doesn’t make something really different than the Arch Component tool in Utils. Not too sure what to do there yet.. Any insight?
Another question I have:
Some people have suggested making separate Windows and Door buttons. As much as I like having a single object that handles all the cases, being a window or a door (the difference is just semantic, really), it indeed makes sense to have separate buttons. There is no need for the UI to reflect exactly how things work internally, and having the UI follow semantic categories seems right. After all, anybody has a very clear idea of what’s the difference between a door and a window.
Such separation could happen with structures too: One could have separate column, beam, and slab tools. There is even another issue there: Arch structure have length, width and height parameters. Height is always what determines the extrusion. But, for a column, it makes sense. For a beam however, it’s counter-intuitive. The length should determine the extrusion. I tried to do that before (if the role of the structure is Beam, the length defines the extrusion) but it didn’t work very well (too many inbetween cases). We could of course have two different classes, one for beams one for columns, but that would bring in a whole series of problems that other bim apps have and that we dont have (unable to change from one category to another, what of all the cases that are neither really a beam not a column, etc), so i’d rather not go that way. So i have no further idea at the moment 
Any opinion?
Maybe a good idea is to integrate the Arch Equipment tool as a button in the BIM Library panel (a downgrade in the UI). When I saw the missing tool, I intuitively looked for the tool in the Library panel. My concern is when I need to create an Arch equipment in BIM WB, what should I do? To change to Arch WB, click on Arch Equipment and then move back to BIM WB? This a question for beginners who look for the functions in the toolbar. The Arch Component tool works but it does not change the icon of the object in the Combo View. And this is not associated with the BIM Library tool, like the previous configuration where I saw BIM Library and Arch Equipment: one for the creation and one for management.
Semantic is very important to facilitate the quick comprehension with people. But In this case, the options for windows and doors are not so different. maybe you could try to change the icon design for this tool. Rather to have an “Arch Window” tool with a window icon. You could change the name to an “Arch Opening” tool with an icon representing both door and window.
I do not see a problem with the concept o term “structure” gathering these three elements. In fact, for an open source project like this with few developers working on it, to have this strong compression of terms in one tool is totally fine and acceptable.
Yes. That could happen. Maybe a note in the panel to clarify the meaning of each term? Only for these special cases.
Window and Door internally treated as same thing in FC seem reasonable for me.
‘Arch Opening’ is also an good idea.
Maybe just an Icon ‘overlapping’ a Window and Door Image will tell what this object is all about.
“Opening” means something else in IFC: It’s the hole in the wall where a window goes. So it’s probably best not to use this word.
Your reasoning about equipment is good @bitacovir. We should indeed add one way or another a button to quickly convert an object to an arch equipment.
What about “Arch Aperture”…
Maybe.. Let’s keep thinking. In any case, a higher priority is certainly to make the whole window/door creation process more intuitive and elegant. After the 0.18 release, I’ll work on the UI of the window tool, and also rework the window types that are in the parts library, so they can be placed, dimensioned and inserted just like the built-in types. So we can start having a pretty decent collection of default windows…
In the Arch Structure tool, you have in the panel a Drawing Mode with Beam and Column as options. This helps a lot to understand that we can create these two elements with this single tool. Maybe something similar in the panel of the Arch Window tool will make more easy to visualise that we can create both windows and doors with it.
But I think that you do not need to split in different and individual tools the options to make them more comprehensible.
“Arch WinDoor” 