Attribute Facet
Specify IFC attributes like Name, Description, and more
Filter or require elements based on IFC attributes - the fundamental data fields defined directly on IFC entities. Unlike properties, attributes are fixed for each IFC class.
Parameters
| Parameter | Required | Description |
|---|---|---|
| Name | Yes | The attribute name (e.g., Name, Description) |
| Value | No | Optional value constraint |
Using in IDSedit
As Applicability
Filter elements by their attribute values:
- Add an Attribute Facet to the Applicability section
- Select the Attribute Name from the dropdown
- Optionally specify a Value to match
Example: Target elements named "W01" by setting Name to Name and Value to W01
As Requirement
Require elements to have specific attribute values:
- Add an Attribute Facet to the Requirements section
- Configure the required attribute and value
Common IFC Attributes
These attributes are available on most IFC elements (inherited from IfcRoot):
| Attribute | Type | Description | Example |
|---|---|---|---|
GlobalId | IfcGloballyUniqueId | 22-character unique identifier | 3cUkl32yn9qRSPvBJhiKDP |
Name | IfcLabel | Short identifier/label | W-001, Door-A |
Description | IfcText | Human-readable description | External load-bearing wall |
ObjectType | IfcLabel | User-defined type classification | 200mm Concrete Wall |
Element-Specific Attributes
Additional attributes available on IfcObject and subtypes:
| Attribute | Type | Description | Example |
|---|---|---|---|
Tag | IfcIdentifier | Instance identifier (serial/asset number) | SN-12345 |
PredefinedType | Enum | Standard subtype classification | SHEAR, DOOR |
Spatial Element Attributes
Available on IfcSpatialElement (spaces, storeys, etc.):
| Attribute | Type | Description | Example |
|---|---|---|---|
LongName | IfcLabel | Full descriptive name | Conference Room A |
Type Object Attributes
Available on IfcTypeObject:
| Attribute | Type | Description | Example |
|---|---|---|---|
ApplicableOccurrence | IfcIdentifier | Entity types this type applies to | IfcWall |
ElementType | IfcLabel | Manufacturer type designation | STC-45 Acoustic |
Attributes vs Properties
Understanding when to use each:
| Aspect | Attributes | Properties |
|---|---|---|
| Definition | Fixed by IFC schema | User-extensible |
| Availability | Limited set per class | Unlimited custom properties |
| Location in IFC | Direct entity fields | In IfcPropertySet relations |
| Performance | Faster to query | Requires relation traversal |
| Use case | Core identification | Extended data requirements |
Rule of thumb: Use Attribute Facet for Name, Description, Tag, and ObjectType. Use Property Facet for everything else.
Value Matching
Exact Match
Attribute: Name
Value: W-001
Pattern Matching
Use restrictions for flexible matching:
| Pattern | Matches |
|---|---|
W-[0-9]+ | W-001, W-123, W-9999 |
.*Wall.* | ExternalWall, WallType_A |
[A-Z]{2}-[0-9]{3} | AB-001, XY-999 |
Empty Value Check
To require an attribute exists but allow any value, leave Value empty.
Common Use Cases
Naming Conventions
Enforce element naming standards:
Attribute: Name
Value: Pattern "[A-Z]{2}-[0-9]{4}" (e.g., DR-0001, WL-0042)
Description Requirements
Require meaningful descriptions:
Attribute: Description
Value: Pattern ".{10,}" (minimum 10 characters)
Object Type Classification
Require user-defined types:
Attribute: ObjectType
Value: Not empty (any value required)
Asset Tagging
Require asset tags for facility management:
Attribute: Tag
Value: Pattern "ASSET-[0-9]{6}"
Space Naming
Require full room names:
Attribute: LongName
Value: Not empty
Attributes by IFC Class
IfcWall / IfcWallType
Name,Description,Tag,ObjectType,PredefinedType
IfcDoor / IfcDoorType
Name,Description,Tag,ObjectType,PredefinedType,OperationType
IfcSpace
Name,Description,LongName,ObjectType,PredefinedType
IfcBuildingStorey
Name,Description,LongName,ObjectType,Elevation
Technical Notes
- Attribute names are case-sensitive (use exact IFC schema names)
GlobalIdis always auto-generated - avoid requiring specific valuesNameandDescriptioncan be null in IFC - use requirements to enforce- Inheritance means child classes have all parent attributes
IFC Schema Reference
For complete attribute definitions by class:
Learn More
For detailed specification information, see the official Attribute Facet documentation from buildingSMART.