After examining the types, structure and logic of different building classification systems, it seems natural to conclude that the national classification systems, like OmniClass from the U.S. and Uniclass 2015 from the U.K., are unfinished. They could still benefit from some improvements as regards the clarity their classification logic and internal structural consistency.
OmniClass and Uniclass 2015 are better suited to classifying not elements themselves, but types of elements as defined by their characteristic properties. If during a building’s design, construction or use (when data that is classified becomes much more relevant) an element’s type is changed, under these national standards the element’s classification code will also change.
Because of the changed reference designations, information links may be lost, and that increases the likelihood of errors in the project’s data storage systems and when exchanging object data.
By contrast, the international standard ISO 81346 classifies elements rather than their properties, and thus offers users greater simplicity, clarity and stability. Using easy-to-understand codes for building elements makes it easier for all the participants of a project to collaborate and share information, no matter where they are in the world.
What’s more, stable designations ensure uniform classification through all the phases of a building’s life: when you modify some element’s type, its classification code doesn’t change.
In any case, I hope that these posts have made clear:
(1) that ISO 12006 is not itself a classification system; and
(2) some factors you can consider to analyse and compare classification systems.
Of course, each national classification has its own strengths – for budgeting or project management or something else. And your choice may also be influenced by a project’s location and who is involved. I suggest trying out a variety of classification systems. Comparing them, considering their structure and logic, will help you select the one that’s best-suited to the needs of any given project.