Different Property Set Names in Versions of Revit

You may have noticed over the years that the naming of property sets in Revit has changed from version to version.

For example, in a model exported from Revit Architecture 2011, the property “OmniClass Number” is located in the “PSet_Revit_Type_Identity Data” property set.

However, when this model is upgraded in Revit 2017, and exported with the out-of-the-box IFC exporter, the property is found under “Identity Data.”

When the IFC Exporter is updated to one of the latest on https://sourceforge.net/projects/ifcexporter/files/2017/, the property is then found under “Identity Data(Type).”

This can cause issues with your rulesets.  For example, the rule below checks to ensure the “OmniClass Number” property is defined for all doors. Notice it is looking for the property under “Identity Data.”

All doors do have this property defined in each version of the model; however, in the screenshot below, you can see that this rule fails for all doors exported from Revit Architecture 2011 and Revit 2017 with the IFC Exporter v17.3 installed.

If you have a mixture of models from different versions of Revit, you can work around the issue by using classification.  More information on classifications can be found here:

Create a classification for the OmniClass property:

Add columns for the various property set names of the property:

Set the classification to the value of whatever property location has a value defined by using “*?” wildcards characters in the property columns and “=[column number]” in the Classification Name column:

Change the property column in the rule the to use the classification of the property:

Instead of the “Property Sets” property group, select “Classification” to use your classification of the property.

After running the check with the modified version of the rule, this rule passes since all doors do have an OmniClass Number defined.

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Different Property Set Names in Versions of Revit

Missing Revit Properties

Occasionally, users find that their Revit properties (Identity Data, Constraints, Other, etc) are missing in their exported IFCs when opened in SMC.   The reason most often is that the IFC2X3 Coordination View 2.0 export setup was used in the IFC Export. By default, the IFC2x3 Coordination View 2.0 setup does not export internal Revit property sets.  Therefore, if you want these properties in your IFC, you’ll need to modify the setup and mark the Export Revit Property Sets check box in the Export Property Sets tab of the IFC Export dialog.

Also, IFC2X3 Coordination View 2.0 does not export Space boundaries.

In SMC, components such as walls, doors, floors, etc. that bind a room normally have a Referencing relation to a space.  This can be useful for instance in a check that every room has at least one door to enter/exit from.  In the IFC Export dialog in Revit, with the Space boundaries drop down set to none, these referencing relations are not included in the resulting IFC. Therefore, if you want these relations, you’ll need to modify the IFC2X3 Coordination View 2.0 setup and set the Space boundaries drop-down box to either 1st Level or 2nd Level in the General tab of the IFC Export dialog.

Alternatively, you can use the IFC2x3 Coordination View* setup, which exports Revit property sets and has Space Boundaries set to Level 1 as its default setting.

More information on exporting to IFC from Revit can be found in the article Exporting an IFC File from Revit to SMC

Missing Revit Properties

Space Groups and Areas in Revit

In a Building Information Model (BIM), it is common to model spaces defined as gross areas, apartment areas, departments, etc. that group other spaces. This is accomplished in Revit through area plans, and the IFC exporter in Revit provides area information in the “Other” property set.

Below is a gross area space named Circulation that contains circulation rooms (as defined in Revit) such as Lobby 102, Stair 132, and Corridor 107, listed in the Space Grouping view:

issue_2017_01_tt_20_01

Notice in the Info view, the “Other” property set contains the Area Scheme ID and Category properties.  The Area Scheme ID provides the name of the area scheme, such as Gross Area, Apartment, etc., and the Category property states whether the space is a room, space, or area.  Also, notice in the Space Grouping view, the Space Group Type column lists Gross Building, which is the same value as the Area Scheme ID.  This value is the classification name from the Space Grouping classification.

If the Corridor 107 room is selected, the Area Scheme ID property is not defined because the category of the space is a room and not an area.

issue_2017_01_tt_20_02

These properties in the Other property set make it simple to classify space groups in SMC using classification rules in the Space Grouping classification.  Below, we’ve added a row to the classification rules that matches any spaces that have the value “Areas” in the Other.Category property. Those area spaces will have their classification name set to whatever the value is of the Other.Area Scheme ID.

issue_2017_01_tt_20_03

You can download this modified space group classification from the link below to try with your own Revit models that contain area plans:

Space Grouping.classification

With your space group classification properly setup, you can use the Space Group Containment rule to check that your space groups contain the required number of space types.

Space Groups and Areas in Revit

Door Operations in Solibri Model Checker using Revit

The direction of door openings can be checked using the Accessible Door Rule (SOL/208) and Escape Route Analysis (SOL/179) rule templates only if door operations are defined.

Within SMC, you can check your model to ensure that door operations are defined by marking the Check Door Opening Direction checkbox in the Model Structure (SOL/176) rule template.

"Check Door Opening Direction" parameter of Model Structure (SOL/176) rule template
“Check Door Opening Direction” parameter of Model Structure (SOL/176) rule template

The BIM Validation – Architectural ruleset that is included in the Rulesets folders of Solibri Model Checker (SMC) contains a rule that ensures door operations are defined.

Results from Door Opening Direction Definition check
Results from Door Opening Direction Definition check

You can also see when a door operation isn’t defined after selecting a door using the Info Tool and viewing its Operation parameter under the Identity Property group.  Those doors that have a missing operation will have the value ‘Undefined’.

Operation property is "Undefined"
Operation property is “Undefined”

When creating single swing doors in Revit, the operation can automatically be set by modeling the Plan Swing subcategories of the doors using the symbolic lines tool.

Below, this Symbolic Line annotation is selected in the Ground Floor view of the Door Family in the Family Editor within Revit.

Plan Swing [projected] Symbolic Line of a door
Plan Swing [projected] Symbolic Line of a door
Notice the subcategory of this symbolic line is set to Plan Swing [projection].  The subcategory can be set to either Plan Swing [projection] or Plan Swing [cut] to designate the swing and thereby populate the operation of the door.

When the exported IFC is opened in SMC, you can see the swing in the footprint as well as the Operation property has the value Single Swing Right.

Door with Single Swing Right operation in SMC
Door with Single Swing Right operation in SMC

If the symbolic line is deleted in Revit, then the door operation in the IFC is no longer populated.

Plan Swing [projection] symbolic line removed
Plan Swing [projection] symbolic line removed
The resulting IFC opened in SMC has an operation listed as Undefined and there is no longer a swing in the footprint.

Door with missing Plan Swing symbolic line in SMC with "Undefined" Operation
Door with missing Plan Swing symbolic line in SMC with “Undefined” Operation

To add the Symbolic Line for the Plan Swing in Revit, click Annotate > Symbolic Line.

Annotate > Symbolic Line in Revit
Annotate > Symbolic Line in Revit

In the Subcategory dropdown list, select either Plan Swing [projection] or Plan Swing [cut].

Setting the Subcategory of the Symbolic Line to Plan Swing [cut]
Setting the Subcategory of the Symbolic Line to Plan Swing [cut]
Select the Center-ends Arc tool in the draw panel. With this tool, you’ll first click a point as the center of the arc, then the start point, and then the end point of the arc.

Center-ends Arc tool in the Draw panel
Center-ends Arc tool

For the center of the arc, click the point where the panel meets the hinge of the doorway.

Selecting the center of the arc
Selecting the center of the arc

For the start-point, click the point where the panel is swung open 90 degrees.

Selecting the start point of the arc
Selecting the start point of the arc

For the end-point, click the point where the panel meets the latch side of the doorway.

Selecting the end point of the arc
Selecting the end point of the arc

When the family is reloaded and the exported IFC is opened in SMC, the operation and swing will return.

The order by which you select the start and end points is very important. If after selecting the center of the arc, you were to swap the start and end points as seen in the two screenshots below, the operation will be reversed in the exported IFC, even though it still appears correct in Revit.

Incorrect start point selected; this should be the end point
Incorrect start point selected; this should be the end point of the arc
Incorrect end point selected; this should be the start point
Incorrect end point selected; this should be the start point of the arc
Door swing is reversed in the resulting IFC when the start point and end points are swapped.
Door swing is incorrectly reversed in the resulting IFC when the start point and end points are swapped.

There are many different door operations, such as sliding, folding, etc., that don’t have a swing to model.  In these cases, you can specify the operation in the Operation parameter of the IFC Parameters group within the family in Revit.

For example, below is an out-of-the-box door from Revit with a Double Door Sliding operation loaded in SMC.  The operation is Undefined.

"Undefined" Operation for Sliding Double Doors
“Undefined” Operation for Sliding Double Doors

To set the operation, open the door in Revit and click the Family Types button in the Properties panel of the Create ribbon.

Create > Properties > Family Types button in Revit
Create > Properties > Family Types button in Revit

Below, we specified the IFC Parameters > Operation property as DOUBLE_DOOR_SLIDING. Notice we used underscores rather than spaces.  This is important, as the value has to come directly from the enumeration IfcDoorStyleOperationEnum from IFC.

Setting the Operation property in the Family Types window
Setting the Operation property in the Family Types window

You can find the listing of valid operation values through this link: IfcDoorStyleOperationEnum

When loaded in SMC, the operation is defined. Note door swings only show up in the footprint of SMC for Single Swing and Double Door Single Swing doors.

Door with "Double Door Sliding" Operation correctly set in the IFC
Door with “Double Door Sliding” Operation correctly set in the IFC
Door Operations in Solibri Model Checker using Revit

Exporting an IFC file from Revit to SMC

If you are using Revit as your BIM Authoring Tool (BAT), in order to get the most out of your checks in Solibri Model Checker (SMC), you’ll want to ensure that the export of your Model to IFC is going to produce a quality file.  The following article provides some explanations, links to documentation, and suggestions for use with SMC.

Install the latest IFC exporter for Revit

The IFC Exporter For Revit updates the out-of-the-box IFC Exporter that comes with Revit. These later versions of the exporter have additional options, export functionality, and bug fixes, so it always recommended to keep up with the latest release. There are two locations where you can find the IFC Exporter for your version of Revit:

Sourceforge.net: http://sourceforge.net/projects/ifcexporter
Autodesk Exchange | Apps: https://apps.exchange.autodesk.com

IFC Mappings

The IFC Export Classes dialog in Revit allows a user to map a Revit Family Category to an IFC Class.  Elements within the model that are of a specific Family Category export to the corresponding IFC Class entered in the IFC Class Name box.  Alternatively, you can enter Not Exported in the box to ignore specific categories during export. To open this dialog in Revit, click File > Export > Options > IFC Options.

IFC Export Classes
IFC Export Classes

An important topic to touch on here is the export of IfcSpaces.  In order to run spatial analysis checks within SMC, you’ll want to ensure that the Rooms category is mapped to IfcSpace.  In addition, if you wish to use space grouping in SMC, for example to group spaces by Gross Area or Rentable Area, then the Areas category should be mapped to IfcSpace as well.  Lastly, if your Revit model contains MEP spaces that need to be checked in SMC, map the Spaces category to IfcSpace as well.  These mappings to IfcSpace stated above are the defaults of the AIA standard, which can be loaded by clicking the Standard button.

However, one mapping that isn’t part of the AIA standard is the mapping of the Grids category to the IfcGrid class.  In order for grids to display in the footprints of a model loaded in SMC, you’ll need to add this mapping.  More information on Grids in SMC can be found here: Grids in SMC and SMV

More information on the IFC Export Classes dialog can be found here: Load and Modify an IFC Mapping File

Information on how you can map to IFC classes within Revit families using the IfcExportAs and IfcExportType shared parameters can be found here: Specify IFC Entities for Families

IFC Export Dialog

Depending on whether or not you have installed the IFC Exporter for Revit, the IFC Export dialog will have either a simple out-of-the-box user interface with limited options or an updated user interface with many additional options that can be saved as setup configurations. In either case, to export to an IFC, click File > Export > IFC to open the IFC Export dialog.

The Out-Of-The-Box IFC Export Dialog

The out-of-the-box IFC Export dialog seen below has 5 settings options.  The most important is the Files of type dropdown, which specifies the format of the IFC export.   SMC supports all 5 formats; however, in most cases, IFC 2×3 can be selected, which is the default version that has been certified for export in Revit.

Out-of-the-Box IFC Export Dialog
Out-of-the-Box IFC Export Dialog

Of the three checkbox options, you should leave Current view only unchecked so the entire project is exported.  With the option marked, if you export from a 3D View which doesn’t allow the display of rooms, space will be missing in the resulting IFC export.  In many cases, the Split walls and columns by story checkbox should be checked so the walls and columns are divided by the floor they are on.  This often comes in handy for dimensions and counts in Information Takeoff (ITO) within SMC, or pinpointing issues with locations of walls and columns when running checks. Export base quantities can be marked for additional property information that can be used in rule checks or ITO reporting.

More information on these settings can be found here: Export a Project to IFC

IFC Exporter for Revit Alternate UI Dialog

If you’ve installed the IFC Exporter for Revit, the IFC Export Dialog is updated with additional options with the ability to store these options as setup configurations.  The IFC Export dialog comes with 9 setup configurations, which are shown below:

IFC Export Dialog
IFC Export Dialog

The following tables outline the different options between the 9 setup configurations.  This first table lists the setup configurations that use the IFC2x3 scheme. As with the out-of-the-box IFC Export dialog, in most cases you should use the IFC2x3 Coordination View setup. As seen in the table below, this setup does not split walls and columns by level.  Therefore, before you export, you should duplicate the IFC2x3 Coordination View setup, which thereby allows you to modify the options to mark the Split walls and columns by level option.

Setup/File Version IFC2x3 Coordination View 2.0 IFC2x3 Coordination View IFC2x3 GSA Concept Design BIM 2010 IFC2x3 Basic FM Handover View IFC2x3 Extended FM Handover View
File Type IFC IFC IFC IFC IFC
Space Boundaries None 1st Level 2nd Level 1st Level 1st Level
Phase to Export Default Phase to export Default Phase to export Default Phase to export Default Phase to export Default Phase to export
Property Sets IFC Common Only Internal Revit, IFC Common Internal Revit, IFC Common IFC Common Only IFC Common, Schedules, User-defined
User-defined Property Sets X
Base Quantities X X X
2D Plan View Elements X X X X
Bounding Box X X
Solid Models When Possible X X
Use Coarse Tessellation for Some Breps X X X X X
Split Walls and Columns X

SMC does support IFC2x3 Coordination View 2.0 and has received the IFC Coordination View 2.0 Import Certification (Click Here).  If you wish to use this setup configuration from Revit, as with the IFC2x3 Coordination View setup configuration, it is recommended that you mark the Split walls and columns by level option.  However, the IFC2x3 Coordination View 2.0 setup does not export internal Revit property sets (e.g Identity Data, Data, Other, etc.). Therefore, you should also mark the Export Revit Property Sets checkbox in the Export Property Sets tab of the IFC Export dialog.

The following table outlines the differences between the setup configurations that use the older IFC2x3 scheme:

Setup/File Version IFC2x2 Coordination View IFC2x2 Singapore BCA e-Plan Check
File Type IFC IFC
Space Boundaries 1st Level 1st Level
Phase to Export Default Phase to export Default Phase to export
Property Sets Internal Revit, IFC Common Internal Revit, IFC Common
User-defined Property Sets
Base Quantities
2D Plan View Elements
Bounding Box
Solid Models When Possible
Use Coarse Tessellation for Some Breps X X
Split Walls and Columns X

The following table outlines the differences between the setup configurations that use the latest IFC4 specification.

NOTE: SMC does not currently support IFC4 files.

Setup/File Version IFC4 Basic Coordination View 2.0 IFC4 Reference View
File Type IFC IFC
Space Boundaries None None
Phase to Export Default Phase to export Default Phase to export
Property Sets IFC Common Only IFC Common Only
User-defined Property Sets
Base Quantities
2D Plan View Elements
Bounding Box
Solid Models When Possible
Use Coarse Tessellation for Some Breps X X
Split Walls and Columns
Exporting an IFC file from Revit to SMC