Comparing classification systems I – The 2 Types

Designers often wonder which digital building classification to use in projects. Which is best? This is in fact a key question for the smooth exchange of information among a BIM project’s participants over the building’s entire life. Let me offer some context for the choice. This first post describes the 2 types of classification systems currently available.

To begin, note that ISO 12006 is often confused with a building product classification system. But that international standard just provides guidelines for developing classification systems that are suited to the building industry – it is not itself a classification system with codes for specific building elements. In other words, you cannot classify the data in a project with ISO 12006.

Since for a long time there was no unified international building classification system, some countries developed their own national systems based on ISO 12006-2. Examples are the U.S. national standard OmniClass, created back in 2006 and significantly augmented in 2012, and Uniclass 2015, the 3rd version of the U.K.’s unified classification system, renewal of which began in 2015.

The Nordic countries also developed national classifiers based on ISO 12006-2: Finland launched Talo 2000 in 2008, Denmark developed DBK between 2003 and 2007, and in Sweden the BSAB classification system was used until 2016. Note that creation of the new Swedish system BSAB 2.0, aka “CoClass”, published in 2016, involved not only ISO 12006-2, but also a second international standard – ISO/IEC 81346.


ISO 81346 gives rules for reference designations of specific industry objects, where elements’ designations are independent of their use type. At first, though, while it was good for manufacturing, it wasn’t suited to classifying building industry objects. Only in May 2018, when part 12 of ISO 81346 was published, did this international standard became apt also for classifying building elements.

At present, then, 2 types of building information classification systems are in use around the world:

  • the international standard ISO/IEC 81346 including part 12, providing rules for structuring systems, component classes for building works and services, and coding principles;
  • and a variety of national-level classifications (based on ISO 12006).

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