The following guidance is provided for Autodesk Revit users exchanging models with Graphisoft ARCHICAD. All information is provided in good faith.
Originally this page formed a page in our standard Post-contract BIM Execution Plan (BEP). However, our growing understanding and technology updates mean that the information in the BEP is quickly outdated. It was becoming increasing difficult to maintain each project document so we decided a better route was to share this advice through a single page. For international readers it should be noted that some of the advice is UK specific only.
This blog piece will be periodically reviewed and updated to reflect the latest advice so our BEP only needs to have a link to this advice. This makes the BEP lighter and the contents will always be up to date for all projects.
This page will also include links to more detailed posts we have already / will share that will support greater understanding of file exchange between ARCHICAD and Revit.
Whilst this page was developed to improve our internal process, please feel free to link to this page. If you have comments or suggestions for improvements please email BIM@bondbryan.co.uk or comment at the bottom of this blog page.
For technical support with an exchange issue relating to Bond Bryan Architects models please email BIMsupport@bondbryan.co.uk.
Files should be exchanged in IFC 2×3 (*.ifc) Coordination View 2.0 where exchanging models with ARCHICAD.
ARCHICAD has certification for IFC2x3 import and export from buildingSMART International. Revit has certification for IFC2x3 export and import when linking IFC files (version 2016 and above) from buildingSMART International.
For exchange Revit users should install and use BOTH of the following:
- Autodesk Revit’s sourceforge app – http://sourceforge.net/projects/ifcexporter/ This covers Revit 2012-2016.
- Graphisoft ARCHICAD Connection add-in – http://www.graphisoft.com/downloads/interoperability.html. Supporting documentation is also available from this link. This add-in fixes a number of known issues in earlier versions and offers additional functionality in newer versions.
Additional add-ins are also available from Graphisoft for earlier versions of Autodesk REVIT. These are available here – http://www.graphisoft.com/downloads/addons/interoperability/Archive.html
Autodesk Revit Export
The following settings should be considered when exchanging models between Autodesk Revit and Graphisoft ARCHICAD:
- Autodesk REVIT users should ensure their Mapping of elements for IFC exchange for both import and export is correct to ensure reliable exchange.
- For projects in the UK, Layers should be exported in line with BS 1192:2007+A2:2016. Whilst Autodesk REVIT doesn’t specifically use layers whilst modelling, these are required by other software for IFC (and DWG) exchange. Layers are determined in the DWG settings and the correct settings should be selected before IFC export.
- Models should be exported from Autodesk REVIT with only the architectural floor levels switched on when sending models to the architect. i.e. switch off additional Building Stories created for structural steelwork levels. These ‘additional’ levels can be switched off by un-ticking the ‘Building Story’ box in the models section/elevation. (Note: this is only available in Autodesk REVIT 2013 and above). In order to make this process of collaboration straightforward, the agreed levels for transfer should be agreed with all team members and documented in a Post-contract BIM Execution Plan (BEP).
- Where Classification References are required to be exchanged between Autodesk Revit and Graphisoft ARCHICAD then the following methodology should be utilised: http://www.evolve-consultancy.com/resource/guides/ifc-classification-revit (courtesy of Nigel Davies at Evolve Consultancy). Note that Revit’s Classification Manager will only exchange parameters and not true IFC Classification References.
Autodesk Revit Import
Some settings by default mean that some model elements are switched off when models are opened in Autodesk REVIT. For example if the ARCHICAD user has selected the “Explode Composite and Complex Profile elements into parts” in the export translator, then these elements will be automatically switched off when the REVIT model opens. These elements can be switched on by using Parts Visibility within Autodesk REVIT.
It is recommended that all models should be reviewed before sending file(s) to another party and also reviewed before opening any received file(s). Any issues with transfer should be communicated to the issuing party and addressed before using the model within the chosen authoring tool.
The following free viewers are some that can be used to review IFC models:
- DDS-CAD Viewer (PC only): http://www.dds-cad.net/downloads/dds-cad-open-bim-viewer/
Note: The software listed here is not endorsed by Bond Bryan Architects and is provided in good faith. BBA are happy to add other free viewers on request.
Model exchange issues
Model exchange issues can be caused by a number of factors. Often these issues are deemed to be put under a single bracket of ‘IFC issues’ but this is too simplistic and often there are easy solutions that can resolve the vast majority of these problems. The following should be considered when reviewing where the issue may lie:
- Modelling – ARCHICAD requires users to create models in a particular way to ensure reliable exchange with Autodesk Revit. IFC exchange from ARCHICAD to Revit (and other software) is more than simply changing the export settings. More information on this subject is covered here: Practical application of IFC & COBie: Model Creation.
- Further understanding of modelling and model transfer – see our interoperability testing blog pieces – site geometry (further posts will be developed in due course).
- Was it modelled or was the data created? Often something may be perceived to have been lost in translation. However it may have not been there in the first place as it was never created! It is important to agree what should be exchanged between each software package. Any suspected loss of geometry and/or data should be reported immediately back to the author for investigation.
- Export settings – export settings control what will be exported from each software. If the right settings aren’t selected then the result may not be as required. For example if a user is expecting quantities then both ARCHICAD and Revit need to tick Base Quantities. Some of the export settings for Autodesk Revit users are described above.
- Import settings – Import allows some functionality to be accessed. Again like export settings these can influence the result you end up with. Before exploring further with troubleshooting it is critical to check that the received model is correct. The modelling viewers are an excellent way to review models – see above. However some of these require a small amount of knowledge about how they work. For example, by default in Solibri, Spaces are not immediately visible in the model. These can easily be switched on but a user needs to know how to do this.
- IFC schema – The schema is standardised and requires models to be delivered in line with the schema. Some tools don’t export correctly for the receiving tool (for example Tekla can not currently export Floor data in the correct location for ARCHICAD to interpret). Revit and ARCHICAD export is largely reliable but sometimes you may need to check the schema supports a certain type of concept you are trying to get to work
- Model location – The need to share models in common coordinates is imperative when federating models. An agreed methodology should be agreed and documented in a Post-contract BIM Execution Plan (BEP). Ensuring this is agreed and tested at an early stage will ensure smooth exchange between ARCHICAD and Revit (and other applications).
- Authoring tool issues – Once the above have been fully explored then you should seek assistance from the appropriate vendor’s support channels or directly with the vendor. Both Autodesk and Graphisoft are responsive to issues. However in order to fix outstanding issues they both need to know about the issues in order to provide solutions. So if you do find an issue then I stress the need to report these!
Known issues from ARCHICAD to Revit
- Site geometry – Elements allocated as ‘Site Geometry’ in ARCHICAD’s Element Classification are not transferred into Autodesk Revit when Link methodology is used and ‘As geometric set (wireframe)’ translator setting is used at export. Solution is to use an alternative translator or change ‘Site Geometry’ to ‘Building Element Proxy’. See ‘Interoperability testing : IFC2x3 site geometry exchange‘ blog post for more information on site geometry exchange with a variety of software.
- Models located a long way from the ARCHICAD origin – Models should such as Site Models must be exported from ARCHICAD solo files and not BIMcloud/Teamwork files for exchange with Autodesk Revit. Models exported from BIMcloud/Teamwork files cause the project base point and survey point in Revit to be the same rather than containing the correct model location. See next point for issue and solution.
- Building model exchange – Models located a long way from the project base point can cause a number of issues including loosing Revit spaces created from ARCHICAD Spaces (Zone Stamps) and items connected to walls moving after updates. Solution is to export ARCHICAD models from a Building Model located near to the ARCHICAD project origin. With this method exporting from BIMcloud/Teamworks is ok.
- Coverings – Note that in ARCHICAD the following elements are classified as Coverings: Ceilings, Flooring & Cladding. This means that Revit will import all of these elements into a single Category.
- Wall height matching door height – Walls which contain a door with the same height will cause the door to disappear in Revit. Walls in ARCHICAD need to be modelled slightly higher than the door to avoid this issue. This is particularly the case for doors modelled in curtain walling.
- Room height – All room (space) heights transfer into Autodesk Revit with a default height of 8 feet / 2438.4 metres irrespective of the space (zone stamp) heights defined within ARCHICAD.
- Door swings – Linking an IFC into Autodesk Revit will result in 2D door swings not displaying correctly. The openings will be available but not the door swing. Opening an IFC or converting the IFC to a native Autodesk Revit file will resolve this issue.
- Connecting elements in Revit to walls exchanged from ARCHICAD – Some walls when converted into Autodesk Revit won’t allow elements to be connected. From our tests this appears inconsistent and we have not been able to isolate the reason for this. This appears to be better with Linked IFC in 2016 but causes other issues as noted above.
Known issues from Revit to ARCHICAD
- Profile Attributes – Extreme care should be taken with attribute management when receiving models from Autodesk Revit (and any other software). This is not an issue on first exchange but can be an issue with subsequent updates. Solution is to manage attributes on each import.
Rob Jackson, Associate Director, Bond Bryan Architects
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