IFC, short for Industry Foundation Classes, serves as a standard for openBIM data exchange. It is often called an exchange format, but this is not entirely accurate since IFC is a schema rather than a format. IFC is a way of archiving or referencing model content, rather than a means of continuous data exchange. In other words, IFC is similar to a PDF in terms of functionality. An IFC file is a frozen copy of the original content that can be viewed, measured, used for clash detection, cost estimation, simulation, and more. However, it should not be edited.
Here is an example of a typical IFC workflow: An architect creates a design model and exports an IFC version to share with the HVAC engineer. The HVAC engineer can reference this file into their own software and use it for coordination. Additionally, the IFC model can be used as a basis for energy analysis. The IFC file delivers sufficient information for the simulation software to read and analyze the IFC spaces in the referenced model. However, the engineer cannot make changes to the referenced model, such as moving a wall or creating an opening for an air duct to pass through. In these cases, the engineer should request the change from the architect. Then, the architect can make the requested change, cut an opening in their model, and create a new IFC file.
Although it is technically feasible to edit an IFC model, it’s not the intended workflow. Most software that imports the IFC model see it as a referenced copy of the original design. Some tools allow making minor edits to an IFC model, such as splitting a concrete slab element for construction phasing, but this is an isolated activity and has no effect on the original design model.
The primary goal of an IFC-based workflow is that each discipline remains the author and owner of their model content. For further information on IFC, please visit www.buildingsmart-tech.org/specifications/ifc-overview.