Author:	AndorSzoke
Creation Date:	2010-06-01
ArchiCAD versions	• ArchiCAD 14
Platform:	• Mac OS X • Windows

Contents

Frequently Asked Questions About IFC
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Frequently Asked Questions About IFC

What is IFC?

IFC - Industry Foundation Classes - is a neutral file format that makes it possible to exchange information between different disciplines and different softwares in the building industry. The IFC format is ISO-certified and can be integrated into any existing quality assurance policies your office may have.

IFC is an object-oriented file format with a data model developed by the International Alliance for Interoperability (IAI). For more information, see: http://www.buildingsmart.com

Who supports IFC?

Most of the major and local structural, MEP and architectural applications support the standard IFC file format. ArchiCAD opens any applications that have been developed on the IFC import/export open platform.

Check the following sites or ask your consultant about the IFC compatibility of any current application:

http://en.wikipedia.org/wiki/Industry_Foundation_Classes#Software_vendors_supporting_IFC

http://www.ifcwiki.org/index.php/Commercial_Software

Why should I use IFC?

The principal benefit of IFC object-oriented file format is its object description. Not only does the IFC protocol preserve the full geometric description in 3D, but it also knows object location and relationships, as well as all the properties (or parameters) of each object.

With IFC input/output, ArchiCAD can communicate with a wide range of structural, mechanical and energy analysis applications. It is important to consider what type of information should be exported to the different disciplines. For example, structural engineers will want the load-bearing parts of the building, while an HVAC consultant will need a richer model with more internal information. Besides preparation, ArchiCAD’s IFC interface enables you to filter the building information model before exporting it.

Predefined (but customizable) Translators help you apply IFC model exchange settings as simply as possible, providing “one-click” export/import solutions.

What information does an IFC model carry?

Building hierarchy (Project, Site, Building, Story, Element)
Element type (wall, slab, column, beam etc.)
Geometry
Material
Properties (standard and custom)
Connections

What functions does ArchiCAD 14 support with IFC?

Element Classification

For more accurate model mapping, you can classify ArchiCAD elements by their “IFC type”. While each ArchiCAD element type has a default counterpart in IFC (which is used if you use the “Automatic” option), you can assign any other IFC type to a particular element – for example, if you have used certain tools to model elements of a different type, such as using the Slab tool to model a ceiling etc.

In collaborating with structural partners, the Structural Function classification can be added to the load-bearing building elements. It also lets you limit the exported IFC model to load-bearing elements only, thereby streamlining the collaboration process.

The Position classification lets you sending a model to a partner (e.g. energy analyzer) who is able to differentiate elements by their location (interior or exterior) in the building.

Model export

The entire current ArchiCAD project, or just its filtered content, can be exported in IFC format. Filtration can be done by selection in the current project view, by visible layers, by building stories, by domain types (structural, HVAC or custom), by element types (e.g. columns, beams etc.), etc.

Model import

The IFC model obtained from another application is always transformed into native ArchiCAD elements. At the same time, it is possible to use the imported elements as a reference, since they can be automatically placed onto their own, protected layers (which are locked to prevent editing). Since the incoming elements or modifications are converted into native format, they become an active part of the architectural model, while retaining their properties (e.g. material, profile) assigned in e.g. the received structural model.

Detect IFC model version changes

As part of an IFC model-based data exchange workflow, ArchiCAD enables you to compare two subsequent versions of an IFC model, to insert and to list the detected changes into the current ArchiCAD model.

Managing functions

The IFC Manager allows you to list the IFC entities generated from the elements of the current ArchiCAD project, to query and edit the IFC properties and settings added to ArchiCAD elements, to add new properties (in addition to the default ones) to IFC entities (and thereby to project elements) for later IFC export, to navigate easily between the ArchiCAD model and the derived IFC model, etc.

What does “detect IFC model version changes” function mean?

With the so-called Detect IFC Model Changes function, ArchiCAD 14 detects the geometric differences between two versions of an IFC model (it compares two IFC files that are two versions of the same project according to the elements’ IFC global unique identifiers), and finds the new, deleted and modified elements. The elements affected by the modifications are generated and merged into the currently running project (that project can also be an empty one). Modifications can be viewed and managed using ArchiCAD’s Mark-Up tool in both 2D and 3D views.

What are the differences between the different IFC formats?

.ifc: the original normal, uncompressed format.
.ifcxml: recommended for architects whose partners’ applications cannot read the original .ifc format, but can manage .xml databases (such as budget, energy calculations, etc.). This is also an uncompressed format, with larger file sizes than the normal .ifc format.
.ifczip: the compressed version of both the normal and the xml-type formats, resulting in file size that is, on average, one-quarter of the original (file size varies depending on model size).

What IFC formats does ArchiCAD 14 support?

By default, ArchiCAD 14 import and export support all the above mentioned IFC file formats of the latest IFC version 2x3. It also supports the import of IFC 2x and 2x2 versions.

Note: To export a file of version IFC 2x2, you can do it with an earlier IFC Add-On, which is available as an ArchiCAD Goodie from GRAPHISOFT’s website.

Which methods can I use to import an IFC file into ArchiCAD?

Use Merge to add the IFC model content (or part of it) to the currently running ArchiCAD project. Merged model data are converted into native ArchiCAD elements, which can then be used as a protected or editable reference. The imported content, used as a reference, is separated from the host project elements, and can be displayed together or independently from the original project data by choosing a visualization technique.

The Open command launches an IFC model as a separate ArchiCAD file, independent of any other project currently open in ArchiCAD. This imported file (or a part of it) can be added later as a reference to the appropriate part of another ArchiCAD project as a Hotlinked Module.

Does Hotlink work with IFC files?

You cannot directly hotlink an IFC file to ArchiCAD. However, if you hotlink a project file that contains data opened or merged from an IFC file, many of the elements’ key IFC properties will be included in the hotlink, because they are defined as part of the ArchiCAD elements. These key properties are: element classification by structural function, position and element type, material (Cut Fill), composites, profiles and layers.

How can I check the result of my IFC model export?

After exporting an IFC model, it is good practice to check the IFC model in an IFC viewer. There are many free IFC viewers on the market that can be readily downloaded:

DDS-CAD Viewer: http://www.dds-cad.net
Nemetschek IFC Viewer: http://www.nemetschek.co.uk/ifc
Solibri Model Viewer: http://www.solibri.com

Additional information can be found at the following Wiki address: http://www.ifcwiki.org

Hint: You may also check your exported IFC file by reopening it in ArchiCAD.

Where can I read more about IFC and the suggested data exchange workflow with other disciplines?

A dedicated chapter (called Interoperability) of the ArchiCAD 14 Help gives a detailed description of the collaboration-related topics including the suggested and effective workflow between the architects and the structural/MEP/energy analysis engineers, the ArchiCAD features that can be used to prepare a model for later data exchange, as well as the IFC-related concepts, skills and all functions.

You can also download the IFC 2x3 Guide in PDF format from the http://www.graphisoft.com/support/ifc/downloads/ site.

How does ArchiCAD collaborate with Revit Structure?

Although both ArchiCAD and Revit Structure can import and export IFC models with their standard File handling commands, GRAPHISOFT has developed a free Add-In for Revit Structure, providing additional features to the bi-directional IFC connection between the two softwares. The Add-In post-processes a previously converted (imported or exported) IFC file in Revit Structure, and improves the imported/exported IFC model.

The GRAPHISOFT Improved IFC Exchange Add-In can be downloaded from the following site:

http://www.graphisoft.com/support/archicad/downloads/interoperability/

How does ArchiCAD collaborate with Autodesk MEP applications?

Although ArchiCAD, Revit MEP and AutoCAD MEP can import and export IFC models with their standard file handling commands, GRAPHISOFT has developed free applications for Revit/AutoCAD MEP, which save IFC files specially enhanced for use in Graphisoft MEP Modeler. When importing the resulting IFC file, Graphisoft MEP Modeler will convert Revit/AutoCAD MEP elements to MEP Modeler.

The ArchiCAD Connection applications for Revit/AutoCAD MEP can be downloaded from the following site: