Property Facet
Specify properties, property sets, and data types
Specify requirements for IFC properties, the most common way to attach custom data to model elements. Properties are organized into Property Sets (Psets) with various data types.
Parameters
| Parameter | Required | Description |
|---|---|---|
| Property Set | Yes | The property set name (e.g., Pset_WallCommon) |
| Property Name | Yes | The property name (e.g., FireRating) |
| Value | No | Optional value constraint |
| Data Type | No | Expected IFC data type (e.g., IfcLabel) |
Using in IDSedit
As Applicability
Filter elements that have specific properties:
- Add a Property Facet to the Applicability section
- Enter the Property Set and Property Name
- Optionally specify a Value to filter by
Example: Target load-bearing walls by filtering for Pset_WallCommon / LoadBearing = TRUE
As Requirement
Require elements to have specific properties:
- Add a Property Facet to the Requirements section
- Configure the required property set and name
- Optionally constrain the value or data type
Standard Property Sets
buildingSMART provides standardized property sets that follow naming conventions:
Pset_ (Property Sets)
Common properties for element types:
| Property Set | Applies To | Common Properties |
|---|---|---|
Pset_WallCommon | IfcWall | LoadBearing, IsExternal, FireRating, AcousticRating |
Pset_DoorCommon | IfcDoor | FireRating, IsExternal, SecurityRating |
Pset_WindowCommon | IfcWindow | IsExternal, ThermalTransmittance, GlazingAreaFraction |
Pset_SlabCommon | IfcSlab | LoadBearing, IsExternal, FireRating |
Pset_BeamCommon | IfcBeam | LoadBearing, Span, Slope |
Pset_ColumnCommon | IfcColumn | LoadBearing, Slope |
Pset_SpaceCommon | IfcSpace | IsExternal, GrossPlannedArea, NetPlannedArea |
Qto_ (Quantity Sets)
Measurement quantities for elements:
| Quantity Set | Applies To | Common Quantities |
|---|---|---|
Qto_WallBaseQuantities | IfcWall | Length, Height, Width, GrossVolume, NetVolume |
Qto_DoorBaseQuantities | IfcDoor | Width, Height, Area |
Qto_SlabBaseQuantities | IfcSlab | Width, Length, Depth, GrossArea, NetArea |
Qto_SpaceBaseQuantities | IfcSpace | GrossFloorArea, NetFloorArea, GrossVolume, Height |
Custom Property Sets
You can specify any custom property set name. Common conventions:
CPset_prefix for company-specific properties- Project-specific prefixes (e.g.,
PRJ_,ACME_)
IFC Data Types
When specifying a data type requirement, use these IFC types:
Text Types
| Type | Description | Example |
|---|---|---|
IfcLabel | Short text (up to 255 chars) | "Type A" |
IfcText | Long text (unlimited) | Full descriptions |
IfcIdentifier | Reference identifier | "W-001" |
Numeric Types
| Type | Description | Example |
|---|---|---|
IfcInteger | Whole numbers | 42 |
IfcReal | Decimal numbers | 3.14159 |
IfcBoolean | True/False | TRUE, FALSE |
IfcLogical | True/False/Unknown | TRUE, FALSE, UNKNOWN |
Measure Types (with units)
| Type | Description | Default Unit |
|---|---|---|
IfcLengthMeasure | Linear dimensions | meters |
IfcAreaMeasure | Area values | square meters |
IfcVolumeMeasure | Volume values | cubic meters |
IfcMassMeasure | Weight/mass | kilograms |
IfcTimeMeasure | Duration | seconds |
IfcThermodynamicTemperatureMeasure | Temperature | Kelvin |
IfcPressureMeasure | Pressure | Pascals |
Special Types
| Type | Description | Example |
|---|---|---|
IfcDate | Date value | "2024-01-15" |
IfcDateTime | Date and time | "2024-01-15T10:30:00" |
IfcDuration | ISO 8601 duration | "P1Y2M3D" |
Value Constraints
Simple Values
Exact match: "Concrete", 100, TRUE
Using Restrictions
For flexible matching, use restrictions:
| Restriction | Use Case | Example |
|---|---|---|
| Enumeration | One of several values | ["1HR", "2HR", "3HR"] |
| Pattern | Naming conventions | FR-[0-9]+HR |
| Bounds | Numeric ranges | >= 10 and <= 100 |
Common Use Cases
Fire Safety
Property Set: Pset_WallCommon
Property: FireRating
Value: Pattern matching ".*HR" or enumeration ["1HR", "2HR", "3HR"]
Thermal Performance
Property Set: Pset_WindowCommon
Property: ThermalTransmittance
Value: Bounds <= 1.4 (W/m²K)
Data Type: IfcThermalTransmittanceMeasure
Area Requirements
Property Set: Qto_SpaceBaseQuantities
Property: NetFloorArea
Value: Bounds >= 10 (minimum room size)
Data Type: IfcAreaMeasure
Custom Project Properties
Property Set: CPset_ProjectTracking
Property: CostCenter
Data Type: IfcLabel
Technical Notes
- Property names are case-sensitive in IFC files
- Property set names are case-sensitive
- When Data Type is unspecified, any type is accepted
- Values are validated against the specified data type
- Unit conversion is handled automatically for measure types
Property Set Reference
For complete property set definitions:
Learn More
For detailed specification information, see the official Property Facet documentation from buildingSMART.