01 May 2018

The RIBA Policy Note Boosting the UK’s architectural exports (May 2018) has 10 recommendations, one of which is for ‘A long-term, cross-government export strategy to promote British expertise in architectural services and the built environment’.

In its discussion of this recommendation, the Note mentions British design expertise, and social, economic and environmental challenges with which the UK has experience and expertise.

But it does not mention technical challenges, such as the adoption of BIM, in which the UK is seen as having world-leading expertise.

As evidence of this, the BIM Level 2 standards developed through the UK’s BIM Task Group are finding their way overseas. One very important example is the development of ISO/DIS 19650-1.2 and 2.2 (currently in draft), adapted from BS 1192:2007 and PAS 1192-2:2013. Standards Australia is involved in this process.

Another example is the adoption overseas of Uniclass 2015, the UK government’s classification system for the construction industry, developed and maintained by NBS, and aligned to ISO 12006-2:2015. This adoption is a logical extension of the genesis of Uniclass 2015.1 A recent instance of overseas adoption is that by an Australian state government agency, Transport for New South Wales (TfNSW).


Classification for TfNSW

In February 2017 an unpublished report commissioned by TfNSW (AECOM, 2017, ASA Asset Classification Review), recommended that TfNSW adopt Uniclass 2015 as a part of its push towards Digital Engineering (DE). As a result, over the past few months TfNSW has been liaising with the Uniclass 2015 team, helping with the development of Uniclass 2015 for the needs of the organisation, to enable its adoption.

TfNSW manages non-services delivery functions for heavy rail, light rail, road, ferry, point to point, regional air, cycling and walking networks across the Australian state of New South Wales. NSW has more than three times the area of the UK but just under an eighth of the population. In mid-2016, TfNSW had engaged AECOM in a consultancy role to provide advice on moving towards ‘digital engineering’, needed to manage its new and current assets. This is the Digital Engineering Scoping Study. As with many such organisations around the world, current asset-management processes varied across TfNSW, and asset data are still paper-based in many cases. One part of this advice was to be a report on classification.

In June 2016, the AECOM team first met with the TfNSW DE team and others (Sydney Trains, Road and Maritime Services NSW, Country Regional Network [NSW rail], and NSW State Transit Authority), led by Simon Vaux, to resolve the process for the classification report. The process eventually agreed had four stages:

  • Evaluation of several TfNSW classification standards.
  • Evaluation of several asset classification systems.
  • Detailed mapping between ASA ACS and the recommended classification system.
  • Recommendations for short- and long-term strategies.


Evaluation of several TfNSW classification standards

Five classification standards developed and/or used by TfNSW were evaluated. These standards were:

  • Asset Standards Authority Asset Classification System (ASA ACS);
  • Woolgoolga to Ballina Pacific Highway Upgrade (W2B) Project Asset Classification;
  • Roads and Maritime Services (RMS) Classification;
  • Sydney Metro (SM) Stage 1 Project COBie Template; and
  • Northwest Rapid Transit (NTR) ORIS Template.

The key criterion for evaluation was compliance with ISO 12006-2:2015 Building construction – Organisation of information about construction works – Framework for classification. Classification systems which predated this standard (which replaced the 2001 edition) were unlikely to comply. Did the classification systems deal only with classification (type-of relationships) or did they address modelling (part-of relationships) as well, excluded in the ISO (Figure 1)?


Figure 1: Two examples of classification on the left, and modelling on the right


Which of the twelve ISO object classes were covered? Did they have just one object class or view in each table, or not? Did they reflect the ISO schema (Figure 2), designed to suit building information modelling (and therefore Digital Engineering)? What non-ISO object classes did they include, and were these compatible with the ISO or not?


Figure 2: Data schema from ISO 12006-2:2015


The ASA is a unit within TfNSW. The ASA ACS was developed over many years and was structured to integrate with the predominant asset management platform Ellipse. Summarising the report, the ASA ACS comprises one table, dealing with seven ISO object classes, and combining modelling and classification. For example, it lists parts of Compressed air systems (modelling) and types of Buildings (classification). Its scope is of course geared to the specific needs of TfNSW and to the O&M view of asset management, rather than to construction at large and to the complete life cycle. It is not aligned to the ISO data schema. However, it is broad enough to be used across all TfNSW projects, and includes an important non-construction, and hence non-ISO object class, ‘fleet’, discussed below. None of the other classification systems reviewed included fleet, but it is clearly necessary.

Likewise the W2B project uses a single table, with multiple ISO object classes, mixing classification and modelling, as do the RMS classification and the NRT ORIS Reference Data Template. All are limited in scope. This approach is evidently quite common in project-based classification systems, and unfortunately cannot properly support Digital Engineering.

The Sydney Metro project uses COBie (Construction Operations Building Information Exchange, developed in the USA and implemented in the UK as part of the BIM Level 2 mandate in 2016), which is not a classification system at all. It requires classification codes to be added against each object in the spreadsheet, but any classification system can be used for this purpose.


Evaluation of several asset classification systems

Eight asset classification systems in the infrastructure realm were evaluated against the same criteria. Australia and New Zealand (ANZ) classification systems evaluated were:

  • NATSPEC National Classification System;
  • Austroads AP-T315-16 Data Standard for Road Management and Investment in Australia and New Zealand: Version 1;
  • One Network Road Classification (NZ); and
  • AS 5488-2013 Classification of subsurface utility information.

Summarising the report, the NATSPEC National Classification System deals with buildings, landscape and municipal work, but not civil transport infrastructure. It comprises a single table dealing mostly with ‘traditional’ construction-phase work results. As such it deals with a good number of Systems and some Products, and some other ISO object classes (Complexes, Entities, Management), in the same table. Accordingly it is not ISO-compliant – it is really a list of sections in the NATSPEC and AUS-SPEC specification systems. The building and municipal silos are entrenched – not conducive to collaborative working. While it is a pure classification table, it does not cover the full life cycle. For some Systems (e.g. Bituminous surfacing systems), requirements are scattered across several classifications (work sections), resulting in duplication – not a good characteristic for a classification system.

Austroads is the peak body for Australian and New Zealand road transport and traffic agencies (collectively responsible for over 900,000 km of roads – the UK had just under 400,000 km in 2016). The draft Austroads Data Standard for Road Management and Investment in Australia and New Zealand includes an inventory or asset register describing 32 object types of several ISO object classes, in a single table. The objects are described in terms of their components (modelling) and properties (specification). The inventory is not an ISO-compliant classification system. A separate report (Austroads Technical Report AP-T333-18 Asset Data Harmonisation Stage III: BIM IFC Alignment Review, March 2018) has subsequently mapped the inventory to Uniclass 2015 and to IFCs, in a gap analysis.

The NZ One Network Road Classification (ONRC) classifies roads in six categories – national, regional, arterial, primary collector, secondary collector, and access. This is important for traffic planning, and for prioritising maintenance, but is not otherwise useful for managing the asset lifecycle.

AS 5488-2013, developed by Austroads, Telstra and others, is only concerned with subsurface utilities – it is specific to one ‘silo’. In Table B3, it identifies a wide range of features and gives each a code, e.g. Cable marker: ECM, but the features span a range of ISO object classes. Accordingly it is not ISO-compliant.

International classification systems evaluated were:

  • Uniclass 2015 (UK);
  • OmniClass (USA);
  • UniFormat II (USA); and
  • Crossrail Project (UK).

Uniclass 2015 is designed to support BIM and DE. Summarising the report, Uniclass 2015 is a multi-table classification system that is aligned to ISO 12006-2:2015 – in particular it has tables for Complexes, Entities and Elements, and for Spaces and Products. However it does not yet have all the recommended tables – the Properties table is missing at the moment, for example, and the Work results table is considered redundant given that there is a Systems table instead, filling in a gap in the ISO between Products and Elements (Figure 2). The classification across tables is aligned as far as possible, facilitating their use along the timeline. Being new, Uniclass 2015 is a live classification system – updates are being published by NBS on a regular basis, largely down to ongoing consultations with industry stakeholders, particularly in transport infrastructure in the UK. Development of this kind is expected to continue indefinitely – it is a dynamic classification system.

OmniClass is an established North American multi-table classification system. However, unlike Uniclass 2015, the tables are all legacy tables and were not developed to be easily used together along the project life cycle. They are not aligned with each other, and several deal with more than one ISO object class. Some of the tables exhibit content bias, e.g. towards healthcare or military projects. Some have transport infrastructure content, and some do not. OmniClass is better aligned to the 2001 edition of the ISO than to the 2015 edition. Critiques of OmniClass and of Table 22 Work results in OmniClass (aka MasterFormat) were published by NBS (UK) in 2013, as a step in the development of Uniclass 2015.

For TfNSW an important issue is its ability to influence the ongoing development of the classification system – in the case of OmniClass it is thought that this would be a challenge, whereas Uniclass 2015 expects this sort of input, confirmed in online sessions between TfNSW and the Uniclass 2015 team.

UniFormat II, used by NSW Health Infrastructure, is an iteration of Table 21 Elements in OmniClass. It covers just one object class and so on its own cannot be used for modelling, or for the whole timeline. It does not deal with transport infrastructure (though a related standard, ASTM E2103, deals with bridge elements), and mixes technically-neutral and technically-specific objects, whereas the Uniclass 2015 Elements table is entirely technically-neutral. The table also contains some non-Element objects – Products and Entities.

The Crossrail Project in London – an east-west 118 km railway through the city – combined the two Elements tables, for buildings and civil works, from Uniclass 1997, and adopted other tables from this classification system, such as Table L Products, and then developed these further to suit the needs of the project. This work is being incorporated into Uniclass 2015. For each asset Crossrail maps classification, function and location – modelling is thus kept separate from classification.


Detailed mapping between ASA ACS and the recommended classification system

This was a two-way gap analysis. Uniclass 2015 was recommended as the preferred classification system, and was used for the mapping. What gaps were in the ASA ACS, relative to Uniclass 2015? What gaps were in Uniclass 2015, relative to ASA ACS? Mapping indicates the extent to which conversion of asset data classified in one system can be converted to another system. For example, 1:1 mappings can be directly converted, digitally, but many:many mappings require human intervention. Only 17% of objects had a 1:1 mapping, and 6% were many:many, but 55% of objects had a 1:0 mapping – they were in ASA ACS but not in Uniclass 2015 (conversely, only about 500 of perhaps 13,000 objects in Uniclass 2015 were in ASA ACS – 96% had a 0:1 mapping). The bulk of these were ‘fleet’.

It is proposed that Uniclass 2015 be developed to accommodate mobile assets and their components (i.e. fleet). This is not as radical as it sounds. Mobile assets can be classified using the classes defined in the ISO, from Entity (e.g. train) down to Product (e.g. door handle). Many of the object classes and sub-classes needed already exist in Uniclass 2015, such as Window systems and Luminaires, though objects specific to mobile assets (e.g. train carriage window system types, tram luminaire types) will need to be added. Some, such as Motive systems, Steering systems and Braking systems, and many of their component Products, do not exist at all, being specific to mobile assets. Some objects might be seen as on a mobility continuum, e.g. Residential buildings – Transportable homes – Caravans – Motorhomes. The first two might be considered as covered under Residential buildings (where transportability is a property), the last two might need a new class, Residential vehicles (where drivability is a property). Some objects that ASA ACS classed as ‘fleet’ might belong in the Uniclass 2015 table TE Tools and equipment. And then there are ‘fleet’ objects not considered in the ASA ACS, such as aircraft and submarines. This all needs to be considered very carefully.


Recommendations for short- and long-term strategies

For the short term, the report recommended that TfNSW align ASA ACS to Uniclass 2015, focussing on filling the gaps. For the long term, the report recommended that TfNSW fully implement Uniclass 2015, and contribute to the development of the classification system. This is underway.


Implementation of Uniclass 2015 by TfNSW

So far in 2018, NBS have added classifications across four tables at the request of TfNSW and other transport providers. Examples of these additions include:

Spaces: Codes for the following have been added:

  • Platforms
  • Cycle storage spaces

Entities: Codes for the following have been added:

  • Access stairways and walkways.
  • Mechanical services buildings.

Systems: Codes for the following have been added:

  • Cast tunnel invert systems.
  • Tunnel and shaft opening systems.
  • Tunnel lighting systems.
  • Fibre optic monitoring systems.
  • Total station monitoring systems.

Products: Codes for the following have been added:

  • Cableway section panels.
  • Railway rolling stock cables.
  • Power quality filter section panels.


We hope that more Australian organisations will follow the lead of TfNSW, and adopt Uniclass 2015. This process is underway. A 2018 report for Austroads, noted above, has recommended that this organisation also engage with the development of Uniclass 2015, and of IFCs, for roads infrastructure. It is also hoped that Curtin University’s SBEnrc (Sustainable Built Environment National Research Centre) Project 2.51, Developing a cross-sector digital asset information model framework for asset management, will consider the use of Uniclass 2015 in its report due September 2018.


Further reading

Uniclass 2015

1 Gelder, J (2015) ‘The design and development of a classification system for BIM’, WIT Transactions on the built environment 149, pp. 477-491.