Tables out for comment

At the time of writing, Uniclass2 tables at externallinkare still out for comment, strictly speaking, and have been since early 2012. We (CPI and NBS) receive occasional comments as architects and others implement Uniclass2 in their systems, perhaps prematurely given the developments outlined below. On their own terms, the tables are in a state of flux, but the tables also do not yet have civil engineering objects rolled out into them comprehensively and with participation from those sectors.

Withdrawal of the Work Results table as redundant

The main change in Uniclass2 over this comment period has been the withdrawal of the Work Results table. This is somewhat ironic as it this table in Uniclass 1997 that got the whole idea of Uniclass2 rolling, but it has become clear that this table is confusing (why have objects got two near-identical codes?), redundant (objects only need one code) and unnecessarily restrictive on the other tables (the number of levels was limited in every case).

Before it was withdrawn the WR table, or an early version of it anyway, was implemented in NBS Create and then in the NBS National BIM Library. Both will need to be recoded for this reason. They will need to be recoded anyway as the various tables have all evolved from that point in time, as Uniclass2 has continued to be developed. Some are now very different from the versions that were current then, especially the Products table.

The main change in Uniclass2 over this comment period has been the withdrawal of the Work Results table ...

Government acquisition of Uniclass2 from CPI

Early in 2014 CPI (Construction Project Information), the agency that commissioned the Uniclass2 tables from NBS, gave the rights to Uniclass2 to the UK government, in the form of the Technology Strategy Board (TSB). This was over concerns about CPI's ability to take Uniclass2 forward, particularly in terms of civil engineering content (CPI had begun work in this area), and operation and maintenance (CPI had ideas for how this would work).

TSB two-stage competition

The TSB has, unusually, commissioned a two-phase competition for the future of Uniclass2 and the 'digital Plan of Work'. NBS is one of three contractors leading teams for phase 1 of this project, which is being run over May and June 2014. The winner of this phase will be given phase 2, and tasked with developing a national classification system for the construction industry. This may, or may not, be Uniclass2. However, my understanding is that the phase 2 contractor will also be given the rights to Uniclass2 itself. I suppose this means that may use only Uniclass2, use both Uniclass2 and a system of their own devising (apart from Uniclass2, no other current systems meet most of the TSB requirements for classification), or use only a classification system of their own devising.

If Uniclass2 is not the 'winner' in this process, then NBS will need to decide whether to run with it unilaterally, or not. It was developed originally for NBS's purposes. However, NBS made its proposals for Uniclass2 development available to the CPI Uniclass work group, which adopted them and commissioned NBS to develop the first tables. CPI's intention was to provide a classification system for adoption throughout the construction industry. This TSB process might still lead to industry buy-in. Indeed, it might lead to Uniclass2 being exported, through 'UKPlc'.

Or it might lead to Uniclass2 reverting to an NBS-unilateral system after all. In either case, it is expected that modelling from Uniclass2 to other classification systems will be required, probably including OmniClass, and the NRM classifications.

After phase 2, the classification system will be operated by the winner on a self-funding basis for 5 years. If the NBS team is appointed to phase 2, then Uniclass2 will be developed as the UK's national (and international) classification system for the construction industry, which was always our hope.

Things to ignore in the old articles

Pending their withdrawal or rewriting, the numerous articles that have been written on classification since 2006, mostly by the author, must be referred to with care. For example, many refer to the Work Results table, which has been withdrawn as noted above. The sample codes used in the articles are often no longer current. The role of CPI is now historical, and so on.

Pending their withdrawal or rewriting, the numerous articles that have been written on classification since 2006, mostly by the author, must be referred to with care ...

Where we are with ISO 12006-2

The international framework standard for construction sector classification, ISO 12006-2, has been under revision for some time. There will be an ISO Working Group meeting in Toronto in October, which should deal with all national comments on the DIS (i.e. draft). This comment period has closed. The UK voted 'yes', subject to its comments being considered by the WG. If other countries have done the same, the new edition of the ISO should be published in 2015. Uniclass2 closely matches the framework at both shallow level (i.e. through implementing most of the recommended tables) and deep level (i.e. through reflecting the standard's timeline and schema). It is the only classification to do so.

If you have any queries on Uniclass2, please contact Sarah Delany at