Terms used in the NATSPEC National BIM Guide, plus others relevant to BIM.

Note: Dark red text indicates that term has its own separate entry in the glossary.


4D BIM A 3D model linked to time or scheduling data. Model objects and elements with this data attached can be used for construction scheduling analysis and management. It can also be used to create animations of project construction processes.

5D BIM A 4D BIM linked to cost data. The time data adds another dimension to cost data, allowing expenditure to be mapped against the project program for cash flow analysis, etc.

AE, AEC, AECFM Abbreviations for Architect/Engineer, Architect/Engineer/Contractor, Architect/Engineer/Contractor/Facility Manager.

Architectural Programming Software (APS) A software application (based on a database) used to analyse and manage data about the spatial requirements of a building (room function type, required proximities to other functions, building service requirements, floor area, etc). It is also used to generate a spatial Program for Design, or brief, for a project and to assess design proposals against the brief.

Attribute Data element for the computer-sensible description of a property, a relation or a class.

Note: An attribute describes only one single detail of a property, of a class or of a relation.

Example: The name of a property, the code of a class, the measure unit in which values of a property are provided are examples of an attribute. [ISO/IEC Guide 77:2008]

Australian Height Datum (AHD) The datum used for the determination of elevation in Australia. The determination used a national network of benchmarks and tide gauges and set Mean High Water as zero elevation.

Binding See Legal status of the Design Model to construction.

BIM Building Information Models or Building Information Modelling. The American Institute of Architects (AIA) has defined BIM as "a model-based technology linked with a database of project information”, and this reflects the general reliance on database technology as its foundation.

BIM Coordination Room A purpose-designed room set up to facilitate the coordination of digital models by members of the BIM Team. It includes IT infrastructure such as cabling, projectors and/or Smart Boards that allow the room’s occupants to view models together for coordination, collaborative design, etc.

BIM Management Plan (BMP) A formal document that defines how the project will be executed, monitored and controlled with regard to BIM. A BMP is developed at project initiation to provide a master information/data management plan and assignment of roles and responsibilities for model creation and data integration throughout the project. BMP is used in preference to BIM Execution Plan in the Guide because it conveys a broader scope.

Building Information Management (Data Definition) Building Information Management supports the data standards and data requirements for BIM use. Data continuity allows for the reliable exchange of information in a context where both sender and receiver understand the information.

Building Information Model (BIM) (Product) An object-based digital representation of the physical and functional characteristics of a facility. The Building Information Model serves as a shared knowledge resource for information about a facility, forming a reliable basis for decisions during its lifecycle from inception onward.

Building Information Modelling (BIM) (Process) A collection of defined model uses, workflows, and modelling methods used to achieve specific, repeatable, and reliable information results from the model. Modelling methods affect the quality of the information generated from the model. When and why a model is used and shared impacts the effective and efficient use of BIM for desired project outcomes and decision support.

Building Management System (BMS) A network of integrated computer components that is used to monitor and control a wide range of building operations such as HVAC, security/access control, lighting, energy management, maintenance management, and fire safety control.

buildingSMART: The name given to the International Alliance for Interoperability (IAI), the pre-eminent organisation promoting interoperability in the construction industry. Key to this strategy is their promotion of IFC, IFD and IDM.

Bulletin A brief update, report or advisory note on an issue circulated to members of the project team.

CAD Computer Aided Design. A geometric/symbol based computer drawing system that replicates hand drawing techniques.

Casework Cabinetry, joinery items.

Computer Aided Facility Management (CAFM) An IT system that supports Facility Management administration. CAFM systems focus on space management issues including the allocation, amount and location of spaces. They also include owner, employee, and cost information. A Computerised Maintenance Management System (CMMS) focuses on facility maintenance and is often part of CAFM. CMMS can manage asset information, maintenance history, equipment documentation, fleet maintenance and staff and subcontractor activities. CAFM and CMMS are often used interchangeably, and for most practical purposes there is little difference between the two systems. See also Integrated Workplace Management System (IWMS).

Computerised Management Maintenance System (CMMS) See above.

CFD Computational Fluid Dynamics. A branch of fluid mechanics that uses computer programs to simulate the behaviour of fluids and gases when interacting with surfaces. In an architectural context CFD is used to analyse airflows around buildings, ventilation patterns, stack effects in multistorey buildings, fire/smoke behaviour, etc.

Conceptual Design The phase of the design process in which the overall scope and nature of the project is determined in response to the site, planning considerations and the client’s brief, budget and program.

Construction BIM Management Plan A BIM Management Plan for the construction phase of a project.

Construction Operations Building Information Exchange (COBie) A system for capturing information during the design and construction of projects that can be used for Facility Management purposes including operation and maintenance. A key element of the system is a preformatted Excel spreadsheet used for recording this information. COBie eliminates the current process of transferring massive amounts of paper documents to facility operators after construction has been completed. COBie eliminates the need for as-built data capture after building handover and helps to reduce operational costs.

Deliverables The product of engineering and design efforts to be delivered to the client as digital files and/or printed documents. Typically, this would be the concept submittal and the corrected final design. A deliverable may have multiple phases.

Design and Construct (D&C) The project procurement method in which the client enters into one contract for the design and construction of a building or project with an organisation, generally based on a building company which provides all project management, design, construction and project delivery services.

Design-Bid-Build (DBB) The project procurement method in which the client enters into separate contracts for the design and construction of a building or project. Design and documentation services are generally provided by a professional design consultancy, the documents are used for bidding (tendering) purposes and the successful bidder, generally a building company, enters into a contract with the client to build the project. Often referred to as the ‘traditional’ method of procurement.

Design BIM Management Plan A BIM Management Plan for the design phases of a project.

Design Development The phase of the design process in which the general relationships represented in the schematic design phase are resolved in more detail. During this phase the dimensions of all major elements are defined and forms of construction finalised.

DOE US Department of Energy.

EXPRESS A standard data modelling language for product data. EXPRESS is formalized in the ISO Standard for the Exchange of Product model STEP (ISO 10303), and standardized as ISO 10303-11.

EXPRESS-G A standard graphical notation for information models. It is a useful companion to the EXPRESS language for displaying entity and type definitions, relationships and cardinality. This graphical notation supports a subset of the EXPRESS language. It is a method for graphically representing EXPRESS-based models.

Facility Management (FM) The process of managing and maintaining the efficient operation of facilities including buildings, properties and infrastructure. The term is also applied to the discipline concerned with this process.

Facility Manager A person responsible for the facility management of buildings, properties or infrastructure.

FF&E Furniture, Fixtures & Equipment.

Geographic Information System (GIS) A system that integrates hardware, software, and data for capturing, managing, analysing, and displaying all forms of geographically referenced information.

gbXML Green Building Extensible Markup Language (XML). A digital file format for exchanging sustainability information in simulation applications.

Globally Unique Identifier (GUID) A unique code identifying each object/space. A GUID should not be confused with “code” in “room code,” “equipment code,” or “space code.” The GUID assigned by the BIM authoring tool persists through room name changes and various other modifications, allowing the object/space to be tracked throughout the project execution process.

HVAC Heating, Ventilation and Air Conditioning.

IDM (Information Delivery Manual) The aim of the IDM is to support the information exchange requirements for business processes within the building construction industry. It provides detailed specifications of the information that a user fulfilling a particular role would need to provide at a particular point within a project. This is in detailed in ISO 29481-1:2010.

IFC (Industry Foundation Classes) A specification for a neutral data format to describe, exchange and share information typically used within the building and facility management industry sectors. The IFC data model consists of definitions, rules, and protocols that uniquely define data sets which describe capital facilities throughout their lifecycles. IFC is the only non-proprietary, open global data model specification available.

Industry Foundation Class (IFC) A system of defining and representing standard architectural and construction-related graphic and non-graphic data as 3D virtual objects to allow data exchange among BIM tools, cost estimation systems, and other construction-related applications in a way that preserves ability to perform analysis on those objects as they move from one BIM system to another. IFC files saved or exported from BIM-authoring software can be used for the following tasks:

  • Coordination of BIM models and related design disciplines.
  • Clash detection.
  • Rules-based checking.
  • Building Code compliance.
  • Sharing models between different BIM-authoring softwares.
  • COBie data derived from BIM models.
  • Energy testing data derived from BIM models.
  • Systems simulation.

IFD (International Framework for Dictionaries) Library. An object terminology library for the building construction industry. The name is used both for the IFD Library and for the organisation running and maintaining it. The simplest description of IFD Library is that it is a kind of dictionary of construction industry terms that must be used consistently in multiple languages to achieve consistent results – this will enable reliable automated communications between applications. The structure of IFD is given in ISO/PAS 12006-3, which is an EXPRESS model with a short explanation of its purpose and use.

Informational See Legal status of the Design Model to construction.

Integrated Project Delivery (IPD) The project procurement method in which the client enters into a contract with a number of organisations including design consultants and building contractors at the earliest stages of the project to create an integrated team. It is characterised by an expectation that the team will work collaboratively to deliver a product that meets the client’s requirements.

Integrated Workplace Management System (IWMS) An enterprise-class software platform that integrates five key components of functionality, operated from a single technology platform and database repository: real estate management, project management, facilities and space management, maintenance management, and environmental sustainability.

Interoperability With respect to software, used to describe the capability of different programs to exchange data via a common set of exchange formats, to read and write the same file formats, and to use the same protocols. Interoperability relies on software developers adopting agreed standards when creating their applications. Interoperability is facilitated by open standards.

Interoperability The Institute of Electrical and Electronics Engineers defines interoperability as “the ability of two or more systems or components to exchange information and to use the information that has been exchanged.” James A. O'Brien and George M. Marakas, authors of Management Information Systems, further define interoperability as ”being able to accomplish end-user applications using different types of computer systems, operating systems, and application software, interconnected by different types of local and wide area networks.” Semantic interoperability refers to the ability to interpret the information exchanged automatically to produce results that are deemed useful by the end users of both systems.

Life Cycle Analysis (LCA) The whole-of-life impact of various initiatives on the environment. In an architectural context LCA is concerned with the impact of the construction and operation of buildings on the environment. This includes assessing the sustainability of building materials (embodied energy, potential for recycling or reuse, etc).

Lead BIM Coordinator A person who performs an intermediary role between the BIM Manager and the modelling team. He/she implements the BIM Manager’s modelling standards and protocols and deals with the day-to-day coordination of team members to achieve project goals.

Legal status of the Design Model to construction:

  • Binding: Imposing a legal (contractual) obligation between the author/s and recipient/s. Used in this context to mean a Design Model that represents what has to be constructed under the terms of the contract.
  • Informational: A Design Model that conveys non-binding information relevant to the project that may be useful to its recipient/s. No formal claims are made about its accuracy and it is provided on an ‘as is’ basis.
  • Reference: A Design Model that is intended to be used for ‘read-only’ purposes such as recording model development at different stages of the project or clash detection. Once Design Models are designated ‘Reference’, they shall not be edited further. Reference Design Models can be used as the basis for bid preparation but cannot form part of the contract documents. A model has to be designated ‘Binding’ for this purpose. Reference models shall be sufficiently accurate for their intended purpose.
  • Reuse: A Design Model authorised by its authors for modification or further development by its recipients.

Level of Development (LOD)

The American Institute of Architects Document E202 – 2008 Building Information Modeling protocol Exhibit defines Level of Development as follows: “The level(s) of Development (LOD) describes the level of completeness to which a Model Element is developed”. It describes the steps through which a BIM element can logically progress from the lowest level of conceptual approximation to the highest level of representational precision The document defines 5 LODs as described below. Each subsequent level builds on the previous level and includes all the characteristics of the previous levels.

The levels defined (with associated content requirements) are:

  • LOD 100 Conceptual: Overall building massing indicative of area, height, volume, location and orientation may be modelled in three dimensions or represented by other data.
  • LOD 200 Approximate geometry: Model Elements are modelled as generalised systems or assemblies with approximate quantities, size, shape, location and orientation. Non-geometric information may also be attached to model Elements.
  • LOD 300 Precise geometry: Model Elements are modelled as specific assemblies accurate in terms of quantity, size, shape, location and orientation. Non-geometric information may also be attached to model Elements.
  • LOD 400 Fabrication: Model Elements are modelled as specific assemblies accurate in terms of quantity, size, shape, location and orientation with complete fabrication, assembly and detailing information. Non-geometric information may also be attached to model Elements.
  • LOD 500 As-built: Model Elements are modelled as constructed assemblies actual and accurate in terms of quantity, size, shape, location and orientation. Non-geometric information may also be attached to model Elements.

Level of Development, by definition, applies to individual Model Elements. When used to describe the BIM model as a whole it is generally taken that all individual Model Elements are of at least that LOD. In practice, strict consistency may not be necessary. A collaboration matrix or Model Progression Specification, as described in Document E202, provides a means of specifying the various LODs required for Model Elements at each phase of the project.

Map Grid of Australia (MGA) A coordinate system based on the Universal Transverse Mercator projection and the Geocentric Datum of Australia 1994. The unit of measure is the metre.

Mechanical Electrical Plumbing (MEP) Referring to this group of building services or the engineering disciplines associated with them.

Mechanical Electrical Plumbing Fire (MEPF) Referring to these building services or the engineering disciplines.

Model View Definition (MVD) An IFC View Definition, or Model View Definition, defines a subset of the IFC schema that is needed to satisfy one or many Exchange Requirements of the AEC industry. A MVD defines a subset of the IFC Schema providing implementation guidance for all IFC concepts (classes, attributes, relationships, property sets, quantity definitions, etc.) used within this subset. It thereby represents the software requirement specification for the implementation of an IFC interface to satisfy the exchange requirements.

NATSPEC The Australian National Building Specification system. Used in this document to describe the worksection classification system used to organise it, or the name of the organisation that produces it.

Object oriented programming A type of programming in which programmers define not only the data type of a data structure, but also the types of operations (functions) that can be applied to the data structure. In this way, the data structure becomes an object that includes both data and functions. In addition, programmers can create relationships between one object and another. Its relevance is that BIM applications apply this technique – physical elements of a building are represented by corresponding program objects which not only describe their geometry and relative position, but also their properties, behaviour and how they interact with each other.

OmniClass The OmniClass Construction Classification System is a classification system for the construction industry, developed by the Construction Standards Institute (CSI) and is used as a classification structure for electronic databases. As the basis of its tables, OmniClass incorporates other existing systems currently in use, including MasterFormat™ for work results, UniFormat for elements, and EPIC (Electronic Product Information Cooperation) for structuring products.

Open source software: Software whose specification is public, without any restriction in access or implementation, and free of charge.

Product Thing or substance produced by a natural or artificial process.

Note: In ISO/IEC Guide 77, the term "product" is taken in its broadest sense to include devices, systems and installations, as well as material, software and services. [ISO/IEC Guide 77:2008]

Property A defined parameter suitable for the description and differentiation of products.

Note 1: A property describes one aspect of a given object.

Note 2: A property is defined by the totality of its associated attributes. ..... [ISO/IEC Guide 77:2008]

Program for Design (PFD) A formal quantitative schedule of spaces and fixtures, furniture and equipment that informs the design process. A detailed development of the design brief. Derived from analysis of the client’s brief, design guidelines and design assessment criteria. It can be manually compiled or generated with the assistance of purpose designed Architectural Programming Software.

Progress BIMs BIM models other than those specified in Final BIM Deliverables to be provided at specified milestones in the project program to demonstrate or record progress. They can be used as a design tool by the design or construction teams only or form part of the deliverables for the client. If Progress BIMs are required, they shall be specified in the BIM Management Plan (BMP) and the following details for each included:

  • Program milestone.
  • Level of Development.
  • Features to be modelled.
  • Recipient, e.g. Design Team only, client.

The same delivery requirements for 3D Geometric Deliverables specified in Final BIM Deliverables apply to Progress BIMs unless otherwise noted in the BMP.

Reference See Legal status of the Design Model to construction

Request for Information (RFI) A documented request for information on a matter from one party to another. They are usually managed through formal procedures agreed by members of the project team.

Reuse See Legal status of the Design Model to construction

Schematic Design The phase of the design process in which the general arrangement of the project, including indicative room sizes and layout, overall form of the building/s and its/their relationship to the site, is determined.

SPD Supply, Processing and Distribution of materials.

Submission Instructions Written instructions outlining the submissions to be made throughout a project, including their format, timing and who is to submit them. They can be part of the project brief.

Superintendent’s Instruction (SI) A written instruction, or a written confirmation of a verbal instruction, from the Superintendent nominated in the contract to the contractor. Generally confined to items that represent a variation to the contract. Also referred to as Architect’s Instructions, depending on the term used in the contract.

Uniformat A classification system for building elements (including designed elements) that forms the basis of Table 21 of the Omniclass system. A product of the Construction Specifications Institute (CSI) and Construction Specifications Canada (CSC).

Variation Order (VO) A written authorisation issued by the Superintendent or client’s agent to the contractor to proceed with work which will result in a variation to the contract sum. Generally issued after the receipt of a quotation for the variation.

Wayfinding All of the methods which people use to orient themselves in physical space and navigate from place to place, i.e. find their way.