Material layers

Compositions export as IfcMaterialLayerSet — every layer with its name, thickness, category and priority.

Needs SketchUp 2026

This writes IFC 4 entities into the file. On 2025, SketchUp’s own export already discarded the data this reads from, and the command refuses to run rather than write into a file that declares itself IFC 2x3. See Supported versions.

Run it

Plugins → Archeform → Add Layers to IFC…, on the .ifc file you exported from SketchUp.

Why it is a separate step

SketchUp’s IFC exporter writes no material entities at all. Not partial ones — none. And IfcMaterialLayerSet is not a property set, so it cannot be smuggled in through the classification dictionary that Archeform uses for everything else.

The only way to get layers into the file is to write them after the fact. It looks like a workaround because it is one; the alternative is shipping IFC without material layers until Trimble extends the exporter.

The entities written are ordinary IFC4. Nothing proprietary, nothing that needs Archeform at the other end.

What is written

Entity	Per
IFCMATERIAL	layer name
IFCMATERIALLAYER	layer — thickness, category, priority
IFCMATERIALLAYERSET	composition, shared between elements that use it
IFCRELASSOCIATESMATERIAL	links the set to its elements

Thicknesses are converted to the file’s own length unit. Priority is written as a ratio from 0 to 1, as the schema requires — a priority of 80 becomes 0.8.

Functions map to the IFC4 category values:

Archeform	IFC
structure	LoadBearing
substrate	Substrate
insulation	Insulation
membrane	Membrane
finish	Finish
air	AirGap

Diacritics are encoded properly, so Železobeton survives into a valid file.

How elements are matched

By Name, not by GlobalId.

SketchUp’s exporter ignores the GlobalId Archeform puts on the element and generates its own, so matching on identifiers does not work. Names — Wall_005 — come through intact.

Caution

That makes duplicate names a real problem. Two walls called Wall_005 both get the composition of whichever was processed first.

Copied storeys are the usual cause. Run the model check before exporting and it is a non-issue.

Verifying

Open the file in your favourite BIM or IFC viewer, select a wall and look for its materials — most viewers put them on a Material tab. You should see the layers listed in order with their thicknesses — 20 / 300 / 150 / 20 for a rendered, insulated masonry wall.

Some viewers read the materials and their categories but do not display the layering in their interface. That is a limitation of the viewer, not a defect in the file.

What is missing

IfcMaterialLayerSetUsage — the geometric relationship between the layer set and the element: the offset from the reference line and which direction the layers run.

Without it a viewer knows the order of the layers but not which side of the wall the first one is on. Adding it is on the roadmap.

See also

• Compositions
• What gets exported