If you have entered the BIM world through Revit (Autodesk) like most of the people, you may have thought that the entire flow and life cycle of your business project is only available within this software or in the Autodesk environment. Or, worse, you may have heard that "doing BIM" is having a 3D model in Revit (Is BIM the same as Revit?).
When you delve into the subject and learn what Building Information Modeling really is and all its scope, you realize that there are hundreds of different flows, with different software, and that each designer has their own preferences.
A key aspect of BIM —its interoperability— is put to the test when multiple designers are working with files of different formats and need to exchange information quickly and accurately. After all, what should you do if Revit doesn’t read .pnl files, or Archicad doesn’t read .prj files, or Solibri doesn’t handle well the .nwd files?
To face this type of problem, the transfer of information (geometric and non-geometric) is carried out with the help of a common extension, called IFC (Industry Foundation Classes).
What is IFC?
Developed by buildingSMART International, the Industry Foundation Classes is a fundamental part of the openBIM practice, which aims to allow the compatibility of flows to be the focus instead of the compatibility of data; that is, that the flow works independently of the software chosen by each designer.
buildingSMART provides a list of certified IFC applications. There, users can check if the software used in their projects supports an openBIM flow, if the flow itself is compatible with this process. Sometimes they can even predict future obstacles and already foresee a solution.
An alternative, also proposed by buildingSMART, when the flow does not support the IFC, is the BIM Collaboration Format (BCF), which is much more limited and does not cover all the uses of the IFC, but can result very useful in the compatibility phase and for revisions.
The first version of Industry Foundation Classes took place in 1996, with IFC 1.0, which came to the market to bring a neutral model to the AEC industry. Over the years there have been some updates: IFC 1.5, IFC 1.5.1 and IFC 2.0.
In October 2000, the oldest version still in use, IFC 2x, which focused on increasing the stability of the platform and information, was published. Shortly after that, a version came out that made the IFC certifications possible, and the following upgrades were the expansion of the capabilities and compatibilities of the extension.
The most popular version is the 2x3, from 2007, which presented several improvements in performance and quality, plus bug fixes from previous versions.
The latest version was IFC 4.0 (initially known as IFC 2x4), in 2013, and it brought along new forms of documentation, as well as support for new construction platforms, structures and services. The most recent version of IFC 4.0 is Addendum 2, published in July 2016, which brought improvements and corrections.
For the future, IFC 5.0, which promises to bring benefits to infrastructure personnel (starting with alignments and then moving on to roads, tunnels, bridges and railways) and to guarantee more flexibility and capacity with parameterizations of the models of all disciplines, is already in its early stages of development.
Currently, the main uses of Industry Foundation Classes are the compatibility of the projects and the planning of the phases of execution of the construction. In addition, many designers use this solution when they work with different software. For example, architects who use solutions such as AECOsim or Archicad and engineers who use Revit or DDS-Cad can take advantage of IFC.
In the compatibility and testing phases of the standards, the Solibri software is a giant platform that makes optimal use of IFC, as well as Navisworks and Navigator. All have their native extensions, but they give this option and flexibility to the flow of a project.
The Industry Foundation Classes allows excellent geometric compatibility in a common environment and export for analysis in other software. However, the export of the information present in the models is not always perfect.
Difficulties when using IFC
Exporting IFC from a modeling software such as Revit to import it into other software such as Archicad can cause the loss of model information. The recommendation is to be very careful when performing these operations so that no data is lost in the process.
The loss of information in CAD workflows seems to resurface when it comes to the IFC format, which makes it difficult to popularize. If we follow the BIM methodology, it becomes clear that the IFC can be extremely useful if we know its limitations. For this, tests must be carried out to ensure that the IFC format can be used in each specific case.
Alternatives for the IFC
As a solution to the above-mentioned bottlenecks, some developers have created plugins or software that translate the files from their environment to that of another developer, often a competitor. For example, TQS (Structural Engineering Software) has an embedded plugin that makes the direct conversion between its program and programs like Tekla and Revit, with its own extensions, like TQR / RQT in the case of Revit.
Other companies, such as Bentley Systems, also have plugins for Autodesk software that allow the exchange of information quickly and accurately, as required by the AEC sector for whom, on occasion, IFC cannot provide a solution.
For other uses, the IFC continues to be an excellent option for compatibility and integration among professionals, which makes the role of a BIM Director essential to ensure the best workflows for each project.
And you? Have you ever worked with IFC? Can you work with a good openBIM interoperability flow or do you prefer native options? What would you like to see in future versions of the Industry Foundation Classes?