The export asks before you know the answer
The sender picks a version while the recipient’s software is still unknown. A wrong guess comes back days later as “it will not open,” after the model has already been revised twice.
IFC versions
IFC2x3 vs IFC4 vs IFC 4.3: which version to export
Every IFC export dialog asks for a version, and the sender rarely knows what the other side will use. The recipient has the opposite question: will my viewer open this? This page compares the three versions in common use in a few lines, then spends its time on what you can actually see once a file is in Fidrel, where all three open and the real differences show up in the data the export carried.
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Where the version choice goes wrong
The version gets blamed for what the export left out
A model that opens with no areas or lengths looks like a version problem. Usually it is not. The quantities depend on what the export wrote into the file, and that is a setting, not a version number.
Newer only helps if everyone can read it
The newest version carries the most, but a project with five trades is held to the oldest tool among them. One recipient who cannot read the new version sends everyone back to the old one.
The three versions in short
IFC 2x3 is the oldest of the three and the one that the widest range of older software still reads. IFC 4 is the later release, with a fuller schema for geometry and properties. IFC 4.3 is the newest and extends the schema to infrastructure, such as roads, rail and bridges. Authoring tools differ in which of the three they offer and in how complete each export is, so a version label says less about a file than the sender’s export settings do. When two people disagree about “the right version,” they are usually comparing different tools, not different versions.
BIM & 3D
What Fidrel does with each version
Fidrel reads IFC 2x3, IFC 4 and IFC 4.3 files, as .ifc or zipped .ifczip, up to 512 MB. The model is built in your own browser, so nothing is installed, and the original file is kept unchanged with the project documents. Once built, the model card shows its version number, the IFC version, the software that wrote it, the file size and the object count on one line. A file written in some other schema is refused with the message that the IFC version is not supported and that the export should be IFC 2x3, IFC 4 or IFC 4.3. Native design files from authoring tools are not read at all; they must be exported to IFC first.
Choosing a version and checking what arrived
Step 1
Ask what the recipient reads
Before you export, ask what the recipient’s own software opens. If they review in Fidrel, IFC 2x3, IFC 4 and IFC 4.3 all work, so the decision falls back to your own software and to what the file has to carry.
Step 2
Drop the file into Upload model
On the BIM models page choose Upload model and drag in the .ifc or zipped .ifczip file. Fidrel reads the file header before anything is sent, so a file that is not IFC, or a version outside the three, is stopped at this point.
Step 3
Read what the header says
The dialog lists IFC version, Exported from, Model view, Coordinates and Size. If the IFC version is not the one you meant to send, cancel and export again; it is cheaper to catch here than after the model is built.
Step 4
Open the model and select an object
Once the 3D model is ready, select a wall or a slab. The object information lists its attributes, type, materials, properties and quantities, and shows straight away whether the export wrote quantity sets for it.
Step 5
Check the quantities panel
Choose Calculate quantities. Count and volume always appear. If the Area and Length columns are missing, the export did not carry them, and a different IFC version would not change that by itself.
What differs in practice: quantities, not the label
Fidrel calculates count and volume from the geometry, and it reads area, length and the model’s own volume from the quantity sets in the file. Those are looked up by quantity name, in a fixed order of preference, whichever IFC version wrote them. That is why two exports of the same building, one in IFC 2x3 and one in IFC 4, can show the same areas, while two IFC 4 exports with different settings do not. The header also names a model view definition. Fidrel shows it in the upload dialog and saves it with the model, but it does not require any particular one. If you want a number to be there, check the quantities panel on the first export, not on the tenth.
What this page does not cover
Fidrel reads IFC 4.3 files, but this page makes no claim about the road, rail and bridge content that version added. Fidrel does not tell you which export settings to use in your authoring software; they live in that software. Fidrel does not convert a file from one IFC version to another; the original is kept unchanged with the project documents. If a recipient needs a specific version, the sender has to export that version again.
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Ask the person who receives the file. If they review it in Fidrel, any of IFC 2x3, IFC 4 and IFC 4.3 opens, so the choice rests on your own software and on what the model has to carry. Check the quantities after the first upload.
Yes. IFC 4.3 is read like IFC 2x3 and IFC 4, up to 512 MB, and the model is built in your browser. This page makes no claim about infrastructure-specific content such as roads, rail and bridges.
IFC 4 is the later release with a fuller schema, but both open the same way in Fidrel. What you see in the quantities and properties depends on what the export wrote, so compare the two files’ results, not their labels.
Area and length are read from the quantity sets in the file, and only when the export includes them. If the panel says the model has no quantity sets, export again with base quantities included and upload the file as a new version.
No. Fidrel shows open IFC models, so native formats from Revit, Archicad, Tekla, Navisworks, SketchUp and other tools must be exported to IFC first. A zipped IFC (.ifczip) is accepted.