@JQL and @paddyclown if you open the Ifc file with a text editor you can see what of your elemento have the problem by following the line with #nnnnn that appears in the error.
There is a Spanish guy that have a wonderfull Youtube channel called IFC Addict. You can learn a lot with him (if subtitles are ok for you…) I don’t recommend his whatsapp chat so you can receive more than 1000 messages in a day 
Thanks! I can understand spanish very well.
Thanks @rtches - the thing is that I’m not going to spend my life in a text editor on my ifc files, it simply confirms that there is still a way to go before Trimble gives us the semi-automated in-house ifc creation that we need. I know progress is being made, but here we have a typical example of where we need more, & quicker ! When you classify something as an ifcSpace object for example, Su should either automatically create the correct FootPrint shape, or ask us to choose one !
Either that, or we just keep calm and carry on regardless & not care if the Validity Checker from bSmart finds minor stuff ?
I’ll check out your Spanish ifc addict, but sadly El Gringo no habla Espanol 
I just had a look at the bSmart page pertaining to ifcSite - https://standards.buildingsmart.org/IFC/DEV/IFC4_2/FINAL/HTML/schema/ifcproductextension/lexical/ifcsite.htm
& even as a native English speaker it’s pretty difficult to understand 
But it would appear that @JQL is right, there can be several “sites” - " A project may span over several connected or disconnected sites. Therefore site complex provides for a collection of sites included in a project. A site can also be decomposed in parts, where each part defines a site section. This is defined by the composition type attribute of the supertype IfcSpatialStructureElements which is interpreted as follow:
** COMPLEX = site complex*
** ELEMENT = site*
** PARTIAL = site section*
The IfcSite is used to build the spatial structure of a building (that serves as the primary project breakdown and is required to be hierarchical)."
So, there we go !
I hope you don’t mind my sharing my opinion of ifc as it isn’t particularly favourable. Perhaps I am missing the overriding global concepts of classification, but I have always felt ifc to be an alien language that fails to communicate how it should be applied to what we do. The earlier post my @MikeWayzovski is a good example which clarifies the application to windows and doors, and is what we need to understand this (much like Layering conventions), but even within that example I find there is confusion between windows and glazing.
The codifying of every tangible element is an impossible task and serves only as a distraction. Given we have failed to even coordinate 2D layering conventions over the last 30 years I don’t hold out much hope for ifc. Meanwhile the builder is stood on site waiting for a drawing with a line from A to B that sets out his task for the day.
I am fortunate that ifc is not a requirement of my work, but I sympathise with those who are trying to apply even the basics, in what must be a huge time sink. I am happy to be corrected, but am I right, that all this is merely to circumvent the commercial interests of the large CAD companies hell bent on ring fencing the use of their software in a collaborative setting?
@DGSketcher You’re mostly right!
I live in one of the most bureaucratic countries in the western world. IFC will be mandatory for 2030 in europe. I’m pretty sure we are going to have the “best” most “accurate” standards possible, which noone will understand. In the end people will say that they made things in Revit so it should be right.
What will happen to me when I have to say that I made things in Sketchup?
I’ll probably have to have someone behind that text work, but for that I’ll have to know how to do it.
5D+ from @Cyentruk helps a lot with that if you have a nice layer structure that matches IFC classification rules and if you find a way to organize your model into a hierarchy that IFC allows and doesn’t hinder your Sketchup workflow.
If you have that layer structure you can also benefit drawings with section cut hatches, from Curic or Skalp plugins, and it can also make it easy for you to create schedules, or quantity take offs.
That’s what I’m trying to investigate.
Exactly, but I’m not trying to circumvent other software companies. I would gladly adopt Archicad, for instance, or BricsCAD BIM. I might still adopt them.
What I wouldn’t like at all, would be to ditch sketchup. I don’t want to change from a very flexible software that can help me on every stage of the process and produces a model as detailed and useful as I want, just because of IFC.
We came so far circumventing all Layout limitations and Construction documentation hinderances in Sketchup, because of how Sketchup is cool to work with.
I rather force an IFC workflow into Sketchup than forcing me out of Sketchup because of IFC.
The industries and built environment that IFC tries to describe is complex and there are many different ways to specify the building blocks. Even locally in the town I grew up, there where two or three definitions of a (standardized!) sized board. There are also brand manufactured products that gain such a popularity that we refer to them as if it is the actual product.
Next to it, we have all kinds of different software, each specialized in a specific branch and different purposes. IFC tries to deal with interoperability between all these differences. It is more about how we describe it then the way. ( eg. try not to think in fileformats, but rather what’s in there and how everything is related in the digital representation of the built assets.
That last aspect is treated differently in each software and since Revit (and Archicad) has mapped all there different families/categories to the right(?) IfcElements, it’s also much easier to start with exporting, because you don’t have to think of it yourself. The classification inside SketchUp takes a little more initiative from the user, but even when it looks simple inside Revit or Archicad, you won’t get far unless the IFC’s are somehow validated against the agreements or BIM Execution Plan (What information do we need from the model)
It is not just a “push the export button” in neither software.
One of the things that is more obvious in SketchUp then in the data-based modelling software is the fact that the export to IFC is an exact copy of the structure in the model tree or outliner, eg. a building element is nested inside a Storey, then in a Building, Site and than the ‘Project’. This currently adds some levels of nesting that makes it harder to work in but since every component acts actually as a ‘little’ SketchUp model inside a SketchUp model, it also makes it very clear how the hiearchy is built up.(Physical=Relational)
Theoretically, one could have this structure:
Project
Site
Building
Storey 1
Building Element
Building Element
Building Element
etc.
Storey 2
Building Element
Building Element
Building Element
etc.
But it makes much more sense to choose at least one of the 22 categories that are filtered out of all the ~870+ available ones ( the interoperabilty layer of the Ifc has 6 groups and we are mostly interested in the IfcSharedBldgElements, which are shown through the filter)
That’s exactly what I’m talking about.
The idea here, for me, is to try to find the best way of creating the model hierarchy, without breaking my Sketchup workflow completely, while still trying to comply with the most important aspects of things.
The issues for me start after the Storey hierarchy level. Those building elements are rather complex in Sketchup and in my projects.
We can have a bathroom, that is the same component in a lot of different places in the project. This is what Sketchup components are there for.
What I’m struggling to know is how to classify those. Bathrooms. The will have doors, coverings, sanitaryware, cabinets and so on, all under a single.
Will that single component always have to be a IfcElementAssembly ?
Will I have to also use IfcElementAssembly for walls, slabs, roofs too?
It makes little sense that a wall has another wall inside, though it makes some sense that a wall has material layers inside.
I like the kiss approach, but will it be enough in the long run, when IFC compliance will be mandatory in Europe?
What I found so far is that if I don’t use IFC Manager plugin, I can mostly keep my standard hierarchy. An IfcWindow can have several IfcWindows inside and it gets imported nicely in the above software.
I could carry on, but I will have to check if it will fail with more common software as revit and archicad or with the ISO standards we will soon have to put in place.
Well, I guess we’re all pretty much groping along in the dark in the sense that since there is no native automatisation in SU for creating the hierarchy, we have to try and work to a logic, then share our files with our eco-systems of engineers & contractors & see how their software “accepts” or not our files and adjust accordingly…
It would appear that progress is being made on the correct addition of PSets to objects so as to convey more & more accurate alpha-numeric information…
What I sorely miss in Su is an intelligent “outliner” pane where I could:
1 - see what I’ve forgotten to classify
2 - isolate by IFCclass
3 - receive prompts as to hierarchy (this would really help junior staff who struggle even more than us “oldies”)
