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What are IFCs? How can they benefit your company and your projects?
Following the certification of Archicad's IFC 2.0 add-on, we asked Graphisoft's director of Virtual Building technologies, John Mitchell, to explain why this was an important development for users, and the building industry at large.
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First of all, what are IAI and IFC?
The IAI is the International Alliance for Interoperability established in 1995 by American and European AEC (Architecture Engineering and Construction) firms to promote interoperability in the industry. The Alliance now has chapters in Europe, Japan, Korea, Singapore, Australasia and America with over 650 member companies. The IAI has created Industry Foundation Classes (IFC) to make interoperability a reality for AEC firms.
What is "interoperability" and why is it necessary?
Interoperability is the ability to exchange intelligent information reliably and consistently between two dissimilar software applications. For a user, it's the ability to utilize data in his application from another project participant on a different system & discipline and vice versa.
Traditional CAD software is based on a two-dimensional drafting paradigm. The member organizations of the IAI and other industry colleagues were frustrated when they tried to share information between their 2D (and some 3D) applications. They could not access data completely, and sometimes not at all. The reason was that there was no standard for defining the parts of a building, which caused duplications, errors, delays, low quality and extra costs. For the non CAD users in the industry - of which there are many - it is almost impossible to access information for costing, construction management, etc, so these segments of the industry have to reinvent everything. This is hardly a productive way to work.
How does the IAI help interoperability?
The IAI has created a standard, IFC (industry foundation class), which is non-proprietary, and available globally to any company and that defines AEC objects. The important concept here is the term "object". Objects, indeed most objects in a building, have geometry, that is, a 3D description. Objects also have properties, like their product name, finishes, and cost. Some objects are "real" like a door; some objects are abstract, like construction cost.
The difference between this and blocks or objects in 2D CAD software is that the IFC are by definition 3D and reside in an integrated model; the assembly of these objects is the facility. Instead of working with 2D entities such as line, arc, text, you work with the objects directly, using their familiar names, like "wall", "slab", "roof", "building."
But what does this do for an architect who is primarily concerned with producing proper documentation?
In this new paradigm consider an HVAC engineer. Traditionally, the architect gives him plans, elevations and typical sections of the building. The engineer has to determine the room usage, calculate room volumes from the plans and sections, determine the construction materials and calculate the HVAC load. Only then is he able to plan the routes and sizes of ductwork, etc, which he sends back as a new layer on the 2D plans the architect gave him.
Contrast that with the IFC approach. The architect sends the engineer the full geometry of the building in an IFC file; the engineer immediately has access to the room volumes, can see if the architect has selected specific construction types for the walls, carcass, etc. The HVAC application, accessing directly now much richer and integrated data from the architect, fills in missing design parameters and sets about designing the ductwork system. This time, his library is based on 3D objects, and his system automates the selection of these once the design system is calculated. Now he returns to the architect his service proposals; not as a set of plans, but an assembly of 3D objects located accurately in the architect's 3D object model. The architect can now truly coordinate, as he refines the design, identifies clashes, and first with the client, then later with construction manager views accurate visualizations of the building.
Imagine you had the same quality data for every engineering discipline!
And applications like Archicad have clever tools that allow you to automate not only the production of traditional design and documentation drawings but also allow you to automatically issue and distribute drawings, with redlining capabilities built in.
It sounds like a good concept, but buildings have many hundreds of parts - who can be bothered to define standards for all these?
The IAI has been working for over 5 years, with its member organizations and major CAD vendors like Graphisoft, to put the standard in place. The latest release of the standard, IFC 2x specifies over several hundred object types and related concepts, which support the core exchange needs of the building industry.
Why are some CAD vendors promoting different approaches, such as XML?
The object model is an integrated database of the facility; a fundamental consideration is the life cycle - inception, design, construction, operation, and demolition. Traditionally, an occupier or owner could not rely on getting adequate data for asset & facility management at the end of the construction stage; the IFC concept allows this information to be passed to all participants of the development at all stages.
IFC versus XML is a false controversy.
The two standards have arisen from requirements at the opposite end of the information continuum. The motivation for IFC is the global support of the representation of buildings and their parts through agreed common definitions. XML is a representation mechanism that is becoming a convenient and simple transport technology. In order to achieve effective product data integration across the extended facility development enterprise, IFC and XML are complementary technologies and both are necessary. ifcXML the XML version of the object model, has just been completed and allows companies to exploit the IAI's global building standard. IFC provides the information description; XML can allow integration with other document and project management system data and for smaller data sets is an alternative exchange mechanism.
How can a firm get started in all this?
If you're an Archicad user, you're well on the way. Why? Archicad is an integrated 3D model system, has been developed from the start on that concept and is currently being used by over 75,000 users worldwide. Archicad provides support for the first two releases of the IFC standard (IFC 1.5.1 and IFC 2.0), and is working, as it has with many AEC application developers in the industry, on the latest release, IFC 2X.
The approach being promoted by the IAI is to undertake a pilot. A pilot typically identifies a process in the facility development that would benefit from automation, access to better data, perhaps high cost. A modest goal is defined by the project team and used to validate the proposed solutions. The pilot commences and implements the new processes and information transfer. As the scope is small the risk is small. Errors can be supported easily by normal means, but the team learns a lot - the new opportunities, advantages, problems, issues to be resolved. And if successful more ambitious projects follow until a body of expertise is developed to undertake this as a matter of routine.
Who can an Archicad user communicate with using IFCs today?
Archicad is currently working with many vendors; for example in the BLIS project, sponsored by VTT and lead by the VISIO product team from Microsoft, over 30 companies have shared development of IFC 2.0 interfaces, 14 of which recently achieved certification, including, of course, Graphisoft for Archicad. Nemetschek® and Autodesk® have 1.5.1 certifications, and a multi-disciplinary group of software vendors are working on IFC 2X solutions.
