~ Industry Foundation Classes eXtensible Markup Language
When a BIM software user exports a model to IFC, it is usually done in a so-called ‘step’ file. Opening a model in a text editor such as ‘notepad’ or ‘WordPad’, will show a text file with line numbers and references. The object types such as ‘WallStandardCase’ are visible as well. Line number references allow the computer to build an entire IFC model.
An ifcXML file contains precisely the same IFC data. The built model in the computer will therefore lead to the same result. The only difference is the way the data is described. When opening an ifcXML file in ‘notepad’ or ‘WordPad’, you will not see any line numbers, but a computer language with brackets such as ‘<‘ and ‘>’.
Whereas in an IFC step file the object types were written in capital letters at the beginning of the line, these data are in an ifcXML file between such brackets.
The manner in which the IFC data is described (the syntax) is different, but the content of the IFC data is the same. These different ways of describing have been developed in order to give software suppliers ample possibilities to support IFC. Both ways of describing each have their own advantages and disadvantages. Neither method is ‘the best’. Usually the step method is used because it is the source and produces the smallest files.