Using Property Mapping

Advantages of data mapping:

You don’t have to enter those data twice (once as ARCHICAD data, and again as IFC data) which have a common meaning as both ARCHICAD data (e.g. Fire Rating) and IFC (FireRating).

You can save ARCHICAD data as a specific IFC model in accordance with a particular standard (e.g. COBie documentation or company standard), a particular collaborative workflow (e.g. MEP, energy analysis, FM), or the capabilities of a particular IFC model receiver application (e.g. Revit, Tekla, Allplan...).

The following IFC elements listed in the Property Mapping tree and their sub-elements (called “child” elements) are mappable:

IfcElement (building, distribution, furnishing and transport elements),

IfcSpace (ARCHICAD Zone)

IfcTypeObject (including all IFC Type Product entities).

Mapping works for ‘single value’-type IFC Attributes and Properties only. Thus:

it works for all text-, label- and logical-type properties,

it does not work, for example, for ‘table-type’ properties,

it does not work for Classification Reference data.

A mapping rule can be assigned at different levels. For example, you can apply a rule at the IfcBuildingElement level, which will be applicable to all of its child elements (e.g. IfcWall, IfcSlab, etc.). However, the mapping rule (which appears in blue type at the child element’s level) can be redefined at the child level. For example, the abovementioned rule could be modified for the IfcWall entity.

If a particular parameter is common to several Library Part elements, you can map its corresponding IFC data in just one step (see examples later).

How to create a Mapping Rule

1.Select the IFC Property which you would like to map. Data in italic type cannot be mapped.

2.Click on the “New Rule” button. The “Empty Rule” field appears.

3.from the “Add Content” drop-down button, select a Rule Content type:

Parameters & Properties (as the Interactive Element Schedule)

Library Part Parameters (as the Interactive Element Schedule)

Static Text

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4.Add fields to the rules. Fields can have types: e.g. “Thickness” is length measure, “Area” is area measure, “Library Part Name” is string. If a rule contains more than one field, the fields are always a concatenation of fields converted to a string. Conversion is based on calculation units (Project Preferences > Calculation Units & Rules). Fields implicitly contain filters: for example, the Wall's “Height” field can only be evaluated for Wall elements. “General” fields are listed at tool levels too and are valid only for that specific tool.

5.Library Part Parameters can be set in two ways:

Library Part dependent: The selected Library Part parameter will be in effect only for elements that contain this parameter. If the Library Part parameter was defined at the Object subtype level, then the parameter mapping will take place for the child elements, too. For example, if we are mapping the “gs_list_cost”variable parameter of the GS Door Object subtype, then the mapping will be in effect for all Doors (and ifcDoors) which are child Library Part elements of the GS Door (such as Door, Double Door, Metal Door, etc.) See examples below.

Library Part independent: the parameter variable (e.g. “gs_list_cost”) will be in effect for the mapping, regardless of which Library Part it was chosen from. For example, if you select the “gs_list_cost” parameter of the Double Door for mapping as a Library Part Independent parameter, then the mapping will take place for every Door that accesses the “gs_list_cost” parameter. If this door parameter is used for mapping at the IfcElement level, then it will be mapping for all IFC entities which are child entities of the IfcElement and which include the “gs_list_cost” parameter (such as Furnishing elements, e.g. Armchair and Chair). See examples below.

//helpcenter.graphisoft.com/wp-content/uploads/ac22_help/115-ifc/GSCostParameterIndep.png 

Note: If the Property Mapping Preset Setup contains a mapping rule involving a Library Part parameter which is not loaded in the project, then the rule, the mapped IFC data, and the mapped IFC Entity data are all shown in red.

6.String-type rules can be split. Separator type, separator position and split type give you several ways to split a string. For example, use a split to cut out a particular fragment of a Library Part Name.

//helpcenter.graphisoft.com/wp-content/uploads/ac22_help/115-ifc/SplitString.png 

You can assign multiple rules to a single property. This is useful, for example, if several tools will generate the same IFC element type. Rules will be applied in the order in which they appear on the user interface: the first valid rule will be applied.

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You can see which elements have a mapping rule assigned: the property is followed by a black chain icon. The same icon is also shown for these elements in IFC Project Manager and in Element Settings.

Some Attribute and Property data come with a predefined mapping rule, which you do not have to create yourself in Property Mapping. Although these rules do not appear in the Map IFC Properties dialog box, they can be seen (if they have values) with a gray chain icon in the IFC Project Manager and Element Settings.

To see these predefined property Mapping rules, see Predefined Property Mapping (Export ARCHICAD to IFC)

Examples of Property Mapping Rules

1.Map the user-defined “Acoustic Rating” property (Options > Property Manager) to the “AcousticRating” property defined for the IfcWall.

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2.Map the “Fire Resistance Rating” parameter of windows to the “FireRating” property defined for the IfcWindow.

//helpcenter.graphisoft.com/wp-content/uploads/ac22_help/115-ifc/MapFireRating.png 

3.Define the “Name” Attribute of IfcWall elements using a combination of Wall “ID” and “Building Material/Composite” Name.

//helpcenter.graphisoft.com/wp-content/uploads/ac22_help/115-ifc/DefineNameAttribute.png 

4.Define the “Name” Attribute for IfcDoorStyle by using a fragment of the Door “Library Part name” + static text “-” + “Width” + static text “X” + “Height” (see splitting string-type rule, above).

//helpcenter.graphisoft.com/wp-content/uploads/ac22_help/115-ifc/NameAttributeDoor.png 

This rule will also overwrite the program’s factory default IfcDoorStyle creation rule (see IFC Type Product) with new IfcDoorStyle names, and will automatically create the corresponding doors (you can double-check the result in the IFC Project Manager).

//helpcenter.graphisoft.com/wp-content/uploads/ac22_help/115-ifc/DoorStyleRewrite.png 

5.Define the “Cost” Property for IfcDoor as Library Part dependent parameter.

For mapping, choose the “gs_list_cost” parameter of the “GS Door” Library Part.

To find this parameter, go to the Add Content drop-down button and choose Library Part parameters. From the appearing dialog box, search for the gs_list_cost parameter as shown:

//helpcenter.graphisoft.com/wp-content/uploads/ac22_help/115-ifc/LibPartContent.png     //helpcenter.graphisoft.com/wp-content/uploads/ac22_help/115-ifc/GSCostParameter.png

//helpcenter.graphisoft.com/wp-content/uploads/ac22_help/115-ifc/dependent_subtype_mapping.png 

The mapping rule is valid for the Library Parts which are child elements of the “GS Door” subtype (e.g “Door”, “Double Door”, “Metal Door”, etc.).

6.Define the “Cost” Property for IfcDoor as Library Part independent parameter. For mapping, choose the “gs_list_cost” parameter of the “Double Door”.

To find this parameter, go to the Add Content drop-down button and choose Library Part parameters. From the appearing dialog box, first select the Double Door library part, then search for the gs_list_cost parameter as shown. However, make sure to add it as a Library Part Independent parameter:

//helpcenter.graphisoft.com/wp-content/uploads/ac22_help/115-ifc/LibPartContent00124.png     //helpcenter.graphisoft.com/wp-content/uploads/ac22_help/115-ifc/GSCostParameterIndep00125.png

//helpcenter.graphisoft.com/wp-content/uploads/ac22_help/115-ifc/independent_entity_mapping.png 

7.Define the “Cost” Property for IfcElement as Library Part independent parameter. For mapping, choose the “gs_list_cost” parameter of the “Double Door”. The mapping rule is valid for not just IfcDoor elements but all other Library Parts which will be converted to IFC Entities that are child element of IfcElement (e.g. IfcWindow, IfcFurnishingElement, IfcDistributionElement, IfcTransportElement etc.) and contain the “gs_list_cost” parameter (e.g “Armchair”, “Desk”, “Basin”, “Sink” etc.).

8.You can apply ARCHICAD data mapping rules to the IFC data of IFC Type Product elements. For example, generate the names of Window types (Name Attribute of IfcWindowStyle) from the combination of the Library Part Name, the Width and Height parameters of Window.

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