With this IFC export manual, the goal is to give the user a guide on how to export the IFC for the right purposes. An IFC file can quickly become heavy and large when you have a lot of information to get out of the model. That is why when exporting an IFC, you need to uncheck unnecessary information. When uploading a model to Catenda, it is not always necessary to have a lot of information and a high level of detail in the model. A little later in this manual we will return to what settings we recommend to make the model a little smaller and a little easier to work with. Here we will go through step by step the most appropriate way to export an IFC from Revit to Catenda.

In this article you will be able to find information about:

Before exporting it is important to make sure that the GUID's of your Revit project are correct.

If the GUID is different from a previous export the objects of newer exports will not be properly linked to the GUIDs in BCF topics.

When you make a new project it will have a unique id.

When Revit is open and you are ready to export, you may want to do the following.

Top left we find "File" tab.

Clicking on the "File" tab will bring up this window.

Here we choose -> Export -> IFC.

Modify setup - This is where we perform the necessary settings for IFC exports.

When we are inside Export IFC we click on Modify setup.

Another window will appear.

This window contains the following tabs:

We'll take you through the various settings.

1. IFC version - Selection of IFC version.

2. File type - IFC type selection.

3. Phase to export

If you have used the phase tool

in Revit, here you can choose and only

export new or existing structures.

4. Space boundaries - are all about how room information can be used further.

a. 1st Level - Ex on use: Quantity withdrawals, FDVU.

b. 2st Level - Ex on use: Energy analysis, light analysis.

5. Project Origin - Project origin, this we put on Current shared coordinates- Present shared coordinates.

6. Split Walls, Columns, Ducts by level - Here you can f. Ex dividing walls horizontal if modeled over several floors.

7. Include Steel Elements - Includes steel components if modeled.

1. Export linked files as separate IFC's

If you want to include the linked files in the IFC you can check this option to do so.

It is recommended that you export each file separately and import each to their own model.

2. Export only visible objects visible in view

IFC file.

3. Export rooms, areas and spaces in 3D views

This option can be useful for selecting areas in the 2D viewer.

4. Include Steel elements, filled

5. Exports 2D plan view elements, filled

regions (scratches).

1. Exports all Revit Property sets (pset / properties)

Here is an example of a wall exported with this option:

Typical properties that show in the properties menu are:

Constraints, Cross-Section Definition, Dimensions, Structural, Identity Data, Other

Typical properties that show in the Identification menu are:

IFC Parameters

2. Export standard IFC properties.

3. Exports calculated quantities of objects.

4. Export batch lists

5. Export one-off Property Set

Classification settings

Here is an example of what classification settings can look like with omniclass.

Name - The name of the classification

Source (Publisher) - The publisher of the classification

Edition - The classification edition

Edition date - The date of the classification

Documentation location - This has to be a valid documentation location

Classification field name

The classification field name is the name of the parameter in your objects that will hold the classification value. This parameter can often be found on the family level.
Edit a family to see its properties

This is what the parameter can look like in the properties

If you have exported your ifc with a classification and imported it as a model to Catenda you will see its classification suggested as a suggested library when creating a new library on the libraries page.
If a value in the property you specified matches with a value in the documentation provided it will be found and can be used to select objects with this value through the classification library you created.

This is about how detailed we have for example. cups or handrails or maybe bicycle wheels. There are 4 different levels of detail.

Extra Low, Low, Medium and High.

When high, it gets the most detailed as shown in the picture below.

When exporting IFCs from Revit to be used in Catenda Hub, we recommend not to set the level of detail to high. There will be a lot of details and extra polygons in models when exported with higher level of detail and this is not always necessary and will make the model navigation slower. This is an example of the difference between exporting with the Extra low and High setting.

The appearance of the model will be close to the same, but the number of polygons will decrease drastically and the navigation in Catenda Hub will be a lot faster.

1. Export parts like standard IFC element.

2. Select this option to allow mixing of BRep and extrusion geometries for a unit.

3. Select this option to use the active view to generate the geometry. Note that this may have unexpected results if used on a non-3D view.

4. Select this option to use the family and type namesfor references.

5. Select this option to use a simplified approach for calculating room volume (based on

extrusion of 2D space boundaries) which is also standard when exporting to IFC 2x2.

6. Select this option to include the height from the Z-offset for local position in IfcSite. Remove the option to exclude it.

7. Select this option to save the generated IFC GUIDs to the project file after export. This will add "IFC GUID" parameters to items and their types and Project information for project, website and building guides.

8. Select this option to export "Bounding box" representations. This option remains automatically selected for GSA export.

9. If you have complex curved elements or shells and they do not display correctly after the IFC export you can select this option. Keep in mind yo that you might produce a very heavy IFC file.

10. Select this option if you want the BAT-ID or the ID of the object to appear as the name of the entity.

11. Select this option if you want the Revit object name to be the name of the entity

It is important that your Revit coordinates are synchronized with the other models in your project so that they end up on the same place.

Therefore measure the coordinates in Catenda Hub with a point measure and specify a coordinate base in Revit at a point that is on the same place as the measured point in Catenda Hub.

You can find this option in the Manage tab -> Coordinates -> Specify Coordinate Base.
​Specify Coordinates at Point

Relocates a model and rotates the model to True North by specifying coordinates for North/South, East/West, and Elevation.

In Revit it is often easier to model on 90 degree angles and you don't want to rotate the whole model.
In this case you can rotate True North instead.
You will find the option in the Position dropdown below Coordinates in the Manage tab.
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1. Project site - Internal

2. Coordinate base -

You can change this setting to make sure your project is oriented towards North

Shared Coordinates - Default

Survey point

Project Base Point

Internal Origin

Project Base Point Oriented in True North

Internal origin Oriented in True North

3. Override

Here you can override the projected Coordinate System Reference
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Here within the IFC options we make the settings for exporting a model to an IFC file. Here you can customize

setup properties for exporting a model to IFC. What was mentioned at the start of this manual is

it is not necessary to bring too much information out of the model. Feel free to tick off unnecessarily

information before export.

It is possible to view grids in Catenda Hub, and if you have these in your Revit model it is in IFC Options you can set grids to be exported in the IFC. By default these are not exported from Revit.