11 August 2020

Introduction from NBS

Since the launch of Uniclass 2015, we at NBS have been delighted with its adoption by industry. We have updated the system quarterly now for the last five years, and have received thousands of new classification suggestions from industry. We are grateful for the engagement and suggestions from large clients such as Highways England, Transport for London, the Environment Agency and the Metropolitan Police. A recent interoperability report by the Centre for Digital Built Britain recommended continued use of Uniclass 2015 within the UK. Furthermore, it has been fantastic to see its adoption internationally. This article from John Gelder explores how Uniclass 2015 is becoming the classification of choice across Australia. It is either recommended or required for work for the Office of Projects Victoria, Transport for New South Wales, the Rail Industry Safety Standards Board and Austroads.

Clearly, the industry needs support in terms of working with and producing well-structured information. At NBS, we have been working through all of the specification and manufacturer product content that we publish and classifying it to the Uniclass 2015 structure. We are pleased to say that this exercise is now complete, and users of the NBS Chorus specification platform and the NBS Source manufacturer product platform can now benefit from it.

A number of different countries around the world are following the UK's approach to BIM. It will be interesting to see how many follow Australia by also embracing Uniclass 2015 for classification.

Over the years, this need for classification has resulted in a multitude of classifications – in different countries, across different disciplines, and even for the same purpose in the same place. This has reflected and reinforced professional and other information silos, frustrating efforts to coordinate, and now stymying digital integration.

Classifications have three levels of use. There are those who design, develop and maintain the classifications. There are those who apply the classifications to information about particular objects, such as manufacturers and model software developers. And then there are designers, specifiers, builders, maintenance workers and others who use the classifications assigned to the objects that they are dealing with without knowing or caring where they came from. The author has operated at all three levels. But for most, object classification is ‘under the hood’. That does not mean that it is not important, and that an appreciation of it isn’t useful.

A classification system is needed – one comprising multiple tables, each for objects of different classes. Just one table, covering one object class, is not enough to serve many needs along the project timeline and across the various disciplines.

Table 1: ISO 12006-2 and three classification systems

ISO 12006-2



Uniclass 2015

A2, Construction information



Form of information

A3, Construction products







A4, Construction agents

Organizational roles






A5, Construction aids



Tools and equipment

A6, Management



Project management

A7, Construction process




A8, Construction complexes


Construction complex


A9, Construction entities

Construction entities by function

Construction entity


Construction entities by form



User activity14





Maintenance activities

Process activities (in development)

A10, Built spaces

Spaces by function

Built space


Spaces by form



A11, Construction elements


Functional systems



Constructive systems


A12, Work results

Work results

Work result

Redundant in Uniclass 2015 (see below)

A13, Construction properties




Classification tables

Individual unrelated classification tables are not enough. Current classifications in use in the Australian construction industry include:

  • The National Classification System (2019), published by NATSPEC.1
  • The classification used to structure the ANZ Standard Method of Measurement of Building Works (2018), published by AIQS and NZIQS (Australian and New Zealand Institutes of Quantity Surveyors, respectively).2
  • The North American OmniClass, Table 22, ‘Work results’ (2012), used by SpecPack.3
  • The project phases classification used in the Australian Institute of Architects ‘Client architect agreement (2019)’.4
  • The property classification used to structure the Australian Building Codes Board ‘National Construction Code’ suite.5
  • The property classification used to structure the Green Building Council of Australia ‘Green Star’ suite.6
  • The buildings classification given in the ABCB’s NCC (2019).7

All seven classifications were developed independently of each other and do not align – they were not intended to be interoperable. The first three concern the same object class; on a given project, it is possible that all three could be used. In particular, it would have been useful if the first two aligned (NCS and the ANZ SMM), so Australian specifications could ‘talk to’ bills of quantities, and vice versa. This was the case in the UK some years ago. The NBS and NES national building specification systems and the RICS standard method of measurement used the same classification (Uniclass 1997, Table J, ‘Work sections for buildings’), enabling interoperability.8 But this has never been the case in Australia and, since RICS (the Royal Institution of Chartered Surveyors) released the NRM (New Rules of Measurement) in 2012, it is no longer the case in the UK.9

Classification systems

A classification system is needed – one comprising multiple tables, each for objects of different classes. Just one table, covering one object class, is not enough to serve many needs along the project timeline and across the various disciplines. The NCC’s partial ‘Entities’ classification is useful at certain stages and to certain users (e.g. architects and other designers, building control authorities), but not to manufacturers and installers. The NCS is, likewise, useful at certain stages and to certain users (e.g. specifiers, quantity surveyors, subcontractors) but is not of much interest to planners or manufacturers.

The system must be coherent. An integrated sequence of coordinated tables is needed to create a coherent object hierarchy. This is especially the case for BIM, in which modelling essentially maps big things to little things. For example, it maps buildings to elements, elements to systems, and systems to products (and vice versa). Since each of these object classes will have its own classification table, it would make sense if they were designed with each other, and modelling, in mind. An incoherent collection of unrelated tables is not good enough.

None of the tables mentioned are part of a classification system of the kind outlined in ISO 12006-2:2015.10 Current classification systems include OmniClass from North America,11 CoClass from Sweden12 and Uniclass 2015 from the UK.13 Table 1 shows how they correlate to the ISO and to each other. Only two might be regarded as coherent – CoClass and Uniclass 2015.

Since Australia has no such system of its own, the question is which of these classification systems should be adopted here, if any? The answer so far has been Uniclass 2015, although this adoption is in its early stages. Among major clients, the Office of Projects Victoria recommends it.15 Transport for New South Wales (TfNSW) requires it, and is actively engaged with NBS in its ongoing development.16 The Rail Industry Safety Standards Board (RISSB) recommends it.17 The use of Uniclass 2015 was recommended to Austroads in 2018.18 Client adoption means that their supply chains will also use it for civil works and for architectural works. However, most States have no requirements for classification in their BIM implementation guidelines. For example, SA does not stipulate an approach to classification, leaving this to the contractor.19 The relevant Queensland document makes no mention of classification.20

As for Australian BIM tools, NBS Chorus uses Uniclass 2015 as its ‘native’ classification system (others can be used).21 The new NBS Source product – for proprietary objects, their geometries and properties – also uses it as the ‘native’ classification system.22 Autodesk Revit, Graphisoft ArchiCAD and Vectorworks 2020 SP3 embed Uniclass 2015 for objects linked to NBS Chorus.23 Both NATSPEC and NZ Masterspec included a requirement that ‘BIM objects shall have a Uniclass 2015 classification assigned’ in the 2018 draft of the Open BIM Object Standard (OBOS), but this has been dropped in the published version.24 However, its use is supported (after a fashion) in the NATSPEC BIM ‘Properties Generator’, along with OmniClass and the NCS.25


1 NCS is free online at: www.natspec.com.au/resources/national-classification-system.
2 ANZ SMM is available to purchase online at: www.aiqs.com.au/imis/AIQS_Website/Shop/Books/AIQS_Website/Public/Shop/Books.aspx.
3 SpecPack is available to purchase at: https://specpack.com.au.
4 These are: Concept Design; Design Development; Town Planning/Development Application; Construction Documentation; Contractor Selection; and Contract Administration. Also in use for project phases is the RIBA Plan of Work 2020.
5 The NCC Volume 1 structure is: Structure; Fire Resistance; Access and Egress; Services and Equipment; Health and Amenity; Ancillary Provisions; Special Use Buildings; and Energy Efficiency.
6 The Green Star ‘Design & As Built’ structure is: Management; Indoor environment quality; Energy; Transport; Water; Materials; Land use & ecology; Emissions; and Innovation.
7 NCC 2019 Volume 1 is free online at: https://ncc.abcb.gov.au.
8 NES (the National Engineering Specification) has since shut down. UK services engineers have largely moved to the services engineering content produced by NBS and first published in 2004.
9 The three volumes of RICS NRM are available to purchase online at: www.rics.org/uk/upholding-professional-standards/sector-standards/construction/rics-nrm-new-rules-of-measurement/.
10 ISO 12006-2:2015, ‘Building construction – Organization of information about construction works – Framework for classification’, ISO, Geneva.
11 The OmniClass tables, including Table 22 mentioned above, are free online at: www.csiresources.org/standards/omniclass.
12 CoClass tables are free online at: https://byggtjanst.se/tjanster/coclass.
13 Uniclass 2015 tables are free online at: www.thenbs.com/our-tools/uniclass-2015.
14 Identified in the ISO, but outside of its scope.
15 Office of Projects Victoria (2020), ‘Victorian Digital Asset Strategy’, Part C Application, pp. 71-73: ‘ The VDAS recommends using Uniclass 2015, as it is ISO certified and a globally recognised and consistent system’.
16 TfNSW (2019), ‘Application of Uniclass 2015 for Transport for NSW’, 6.2, ‘Our decision’: ‘TfNSW has selected Uniclass 2015, developed by the NBS… as the preferred classification system. The choice to adopt Uniclass 2015 follows comprehensive analysis of the current state, and comparative research of available classification systems, industry-wide, against ISO 12006.2:2015’.
17 RISSB (2019), ‘Digital Engineering: Code of Practice’,part 6.3, ‘Project data classification’: ‘This Code of Practice recommends the use of Uniclass 2015 as the adopted classification of assets and locations during the project lifecycle’.
18 Austroads (2018), ‘Asset data harmonisation Stage III: BIM IFC alignment review’.
19 Department of Planning, Transport & Infrastructure (2019), ‘Project controls: Master specification – PC-EDM5 Digital engineering’: ‘The DEXP [Digital Engineering Execution Plan] shall include the Contractor’s approach to… Asset Classification Matrix’.
20 Department of State Development, Manufacturing, Infrastructure & Planning (2018), ‘Digital enablement for Queensland infrastructure: Principles for BIM implementation’.
21 NBS Chorus (Australia) is available to purchase at: www.thenbs.com.au.
22 NBS Source launched in the UK in April 2020: www.thenbs.com/nbs-source.
23 For the various NBS plug-ins, see: www.thenbs.com/our-tools/nbs-plug-in-for-autodesk-revit.
24 OBOS is free online at: https://bim.natspec.org/documents/open-bim-object-standard.
25 The ‘Properties Generator’ is free online at: www.propgen.bim.natspec.com.au/pages/178534.html.