IFC Schema

Data schema and structure for IFC models

The IFC connector exports data from Industry Foundation Classes (IFC) files, preserving the IFC spatial structure.

Hierarchy

IFC models follow the IFC spatial structure:

The hierarchy reflects IFC’s spatial decomposition:

• Project - The IFC project
• Site - The site/building site
• Building - The building
• Storey - Building floor/level

Object Type

IFC models use standard DataObject (not a connector-specific extension):

{
  "id": "string",
  "speckle_type": "Objects.Data.DataObject",
  "applicationId": "string",
  "name": "string",
  "properties": {
    "string": "any value"
  },
  "displayValue": ["Base (geometry objects)"],
  "units": "string"
}

IFC elements are represented as DataObjects without connector-specific extensions. All IFC-specific data is in the properties field.

Properties

DataObject properties contain IFC property set data:

• IFC Property Sets - IFC property set definitions (Pset_*)
• IFC Type - The IFC entity type (IfcWall, IfcDoor, etc.)
• IFC GUID - The IFC global unique identifier
• IFC Attributes - IFC entity attributes

{
  "properties": {
    "IFC Type": "IfcWall",
    "IFC GUID": "3xKj$l5n1H5QvzJp7xH9$A",
    "IFC Attributes": {
      "GlobalId": "3xKj$l5n1H5QvzJp7xH9$A",
      "OwnerHistory": {...},
      "Name": "Basic Wall",
      "Description": null
    },
    "Property Sets": {
      "Pset_WallCommon": {
        "IsExternal": true,
        "LoadBearing": false,
        "FireRating": "2h"
      },
      "Pset_Construction": {
        "ConstructionMethod": "In-situ"
      }
    }
  }
}

Proxies

IFC models use:

RenderMaterial

Material assignments for visual representation. Referenced by objects via applicationId.

Level

Level proxies encode IFC storey/level definitions. Objects reference levels via Level proxy objects.

Example: IFC DataObject

{
  "id": "ifc-abc123...",
  "speckle_type": "Objects.Data.DataObject",
  "applicationId": "ifc-guid-456",
  "name": "Basic Wall",
  "properties": {
    "IFC Type": "IfcWall",
    "IFC GUID": "3xKj$l5n1H5QvzJp7xH9$A",
    "IFC Attributes": {
      "GlobalId": "3xKj$l5n1H5QvzJp7xH9$A",
      "OwnerHistory": {...},
      "Name": "Basic Wall",
      "Description": null,
      "ObjectType": "Basic Wall",
      "ObjectPlacement": {...},
      "Representation": {...}
    },
    "Property Sets": {
      "Pset_WallCommon": {
        "IsExternal": true,
        "LoadBearing": false,
        "FireRating": "2h"
      },
      "Pset_Construction": {
        "ConstructionMethod": "In-situ",
        "Material": "Concrete"
      }
    }
  },
  "displayValue": [
    {
      "speckle_type": "Objects.Geometry.Mesh",
      "vertices": [0, 0, 0, 10, 0, 0, 10, 0, 3, 0, 0, 3, ...],
      "faces": [0, 1, 2, 0, 2, 3, ...],
      "units": "meters"
    }
  ],
  "units": "meters"
}

Invariants and Caveats

1. Standard DataObject - IFC uses standard DataObject, not a connector-specific extension
2. IFC spatial structure - Hierarchy follows IFC’s Project → Site → Building → Storey structure
3. Property Sets - IFC property sets are in properties.Property Sets
4. IFC GUID - The IFC global unique identifier is in properties.IFC GUID and properties.IFC Attributes.GlobalId
5. No Info fields - IFC models don’t include Info fields
6. IFC compliance - Data structure follows IFC Data schema conventions

How do I find elements by IFC type?

Filter DataObjects by properties.IFC Type. For example, to find all walls: filter where properties.IFC Type == "IfcWall".

What's the difference between IFC GUID and applicationId?

• IFC GUID: The IFC global unique identifier (format: 3xKj$l5n1H5QvzJp7xH9$A)
• applicationId: Speckle’s identifier for the object (may be the same as IFC GUID, but could be different)

Use IFC GUID for IFC-specific workflows. Use applicationId for Speckle references and proxies.

Related Documentation

• Object Schema - Base object structure
• Proxy Schema - How proxies work