Using Revit and dRofus with IFC

This page contains some guidelines on how to use dRofus and Revit through IFC exchange. Please let us know if you have any suggestions or have any questions about this.

To be able to link information in dRofus with information in Revit, there has to be a common key between them. This key has to be the room number and article number from dRofus. Using the identifiers from dRofus in Revit from the beginning will save a lot of work!

1. On rooms/spaces, use the room function number from dRofus as the room number in Revit (put it in the “Number” parameter on the room or in the schedule is preferred). You could either write them in manually or use the Revit plugin to help keeping the room schedule up to date.
2. On Family Symbols, use the FFE number from dRofus on the name on the Revit Family Symbol. If this is not descriptive enough, you could add more text to the name parameter as long as the FFE number from dRofus is at the beginning of the text.

As long as you follow these two points, you will be able to compare and check the model against dRofus through IFC. It is also important to be aware of the attribute “To be drafted” on the FFE objects in dRofus. This is because this is used when comparing dRofus with the model later on.

To export an IFC file from Revit select menu: “R → Export → IFC”. See also export options hot to customize this. In order to get the calculated area values for the spaces you should also check the “Export base quantities”:

You can then open this file in dRofus and use this file to compare and update data in dRofus. To open this in dRofus select the menu option: “dRofus → IFC → Open IFC file”. The first time you open a file you must select what configuration to use. If you have put the room function number in the Revit attribute Number and FFE number in the name you can choose the configuration Revit. Otherwise you must contact us and we will help to create the correct configuration:

Once you have opened the file in dRofus - no data is actually imported or updated. You have to select what data to update in order to update either from dRofus to the IFC file (add information to the ifc model) or update data in dRofus from the ifc file. To do this, right click on some selected rooms or a room level and select “Synchronize with model”. Depending on your access rights and selected ifc configuration you can then update data in dRofus based on information in the IFC File.

In IFC, every equipment has a relation to what building object they belong to. Unfortunately in Revit 2009 and 2010 exports this equipment have relation to the building storey they are placed on, and not in the room. But in order to know what equipment is in what room we need to create that relation. In dRofus you can create that relation based on geometry (if an equipment “fits” within a room we create that relation). Right click on an building storey (or building or project) and select “Fix equipment relation”. Note that this can take a couple of minutes.

Note that you don't have to do the “Fix equipment relation” step when using Revit 2011.

Once you have loaded the ifc file in dRofus you can open the room view to compare the rooms in dRofus with the rooms in the ifc file. You can then navigate both using the defined functions in dRofus or the building structure (floors). In the tree view you also can have a quick link to some reports which gives overview of rooms only in the model and rooms only in the dRofus. If you want to update dRofus with information from the model (e.g. actual area, architect number etc) you have to select synchronize with model.

Once you have loaded the ifc file and fixed the room relations (if you use Revit 2009 or 2010) you can use the ifc file to compare equipment in the model with the planned equipment in dRofus.

If you open the FFE overview you can see a match between the planned FFE in dRofus and the type objects from Revit. Revit will export two type objects for the same family type if they have different orientation. In addition to the normal tree structure with the FFE from dRofus you can also navigate the type objects based on ifc classes.

In order to check/compare planned FFE in dRofus with the drawing right click on some selected rooms or a room level and select “Check equipment in room against model”. You will then get a list with all the errors/warnings. The easiest is then to mark a row in the list and click “Ctrl + E” to export this list to Excel. In the column “type” you have three different types:

1. There are unknown FFE objects in the room that does not match any planned instances.
2. There are not enough FFE objects in the model that matches the planned (with property to be drafted false) in this room.
3. There are not enough FFE objects in the model that matches the planned (with property to be drafted true) in this room.

It is possible to match the FFE in dRofus against the Family Type in Revit using an alternative identifier if needed. Use the BIM ID attribute on the FFE to tell dRofus which Family Type this should be matched against.

You can customize how Revit exports different objects in the project to IFC. It is recommended that you are familiar with this part of the Revit help file about export to IFC.

In the menu: “R → Export → Options → IFC Options” you can define how Revit exports different types of objects and map them to the corresponding IFC object.

By setting a value to “Not Exported” will exclude thise object types from the export. If you only want to use ifc to compare space/areas in dRofus and you are not interested in other objects you can load a file like this: exportlayers-ifc-only-space.txt. If you load this file and then do an ifc export you will get an ifc export with only the rooms. This will be much smaller than a file with all objects. You can also use this settings to define how different type objects should be exported. For example is “Specialty equipment” default exported to IfcBuildingElementProxy (proxy element). From Revit proxy elements does not have a corresponding type object so you are not able to get a full comparison from the FFE overview. You can use this dialog to change this to export as IfcFurniture instead. Then the export will also include type information. An example file that only exports spaces and furniture (Furniture, Casework and Specialty equipment) you can use: exportlayers-ifc-only-space-and-equipment.txt

The export options explained above will let you customize how to export to IFC for each export. But if you share a family object in multiple projects and files you can also define how to export a given type object on the family type it selves. For example if you have some medical equipment you would like to export as IfcFurniture instead of proxy element you can set type to IfcFurnitureType and export object to IfcFurniture. Follow the instructions given here to do this: Specifying IFC Entities for Families