Building information modelling (BIM)
Also: Building information modeling, Building information model
Quick definition: The use of a shared digital representation of a built asset — its geometry, properties and related documents — to support design, construction and operation decisions with reliable information.
Explanation
Beginner explanation
Think of BIM as building the project twice: once on the computer, then for real. Instead of separate drawings that each have to be updated by hand, the team works from structured digital models in which a wall, a pipe or a door "knows" what it is, how big it is and what it is made of. Drawings, schedules and quantities can then be produced from that information, so they stay consistent with each other.
Technical explanation
In current international terminology BIM is treated as a process supported by information models rather than as a type of software. ISO 19650-1 places BIM inside a wider information-management framework: the value comes from defining what information is needed, producing it in a structured and checkable form, and exchanging it through a managed process (Common data environment).
A BIM workflow typically combines object-based 3D models, non-geometric (alphanumeric) data attached to model objects, and associated documents. Models from different disciplines are combined into federated models for coordination, and information is exchanged in native formats or open formats such as Industry Foundation Classes. The amount and reliability of information expected at each stage is set by the Level of information need (or, in North American practice, by Level of development tables).
"BIM" is used in three overlapping senses: the model (building information model), the activity of producing it (modelling) and the overall management discipline. Context usually makes the sense clear, but contracts should say which is meant.
Practical example
On a new municipal recreation centre, the architect, structural engineer and mechanical engineer each produce a discipline model. Every two weeks the models are federated and checked for conflicts. The owner's facilities team has asked for room data, equipment tags and warranty information, so those fields are populated in the models and verified before handover, giving the operations team a usable asset register on day one rather than a box of PDFs.
Why it matters
BIM reduces the cost of inconsistency. Coordinated information lowers the number of field conflicts, RFIs and rework, supports more reliable quantities and schedules, and gives owners structured information for operations. Its benefits depend on defining requirements up front; a detailed model nobody asked for — or nobody can use — adds cost without value.
Common confusion
BIM is not a product or a 3D model on its own. It is also distinct from Virtual design and construction, which uses models together with process and organization metrics to manage project performance. "Level of detail" in a BIM model is a separate idea — see Level of development and Level of information need.
- Virtual design and construction (VDC) — VDC adds process and organization models and performance metrics.
Discipline notes
- General contracting: For contractors, BIM is mainly a coordination, constructability, sequencing and quantity tool; the model is often used to plan trades and verify prefabrication.
- Facilities management: For owners and operators, the useful output is usually the structured asset data, not the 3D geometry.
Historical context
The underlying idea of a computable building description predates the acronym: Charles Eastman and colleagues at Carnegie-Mellon described a "Building Description System" in 1974. The phrase "building information model" appears in academic literature in 1992 (van Nederveen and Tolman). The term "Building Information Modeling" was popularised in the early 2000s, notably through a 2002 software-vendor white paper and industry commentary in 2002–2003. International standardisation of BIM-based information management followed with ISO 19650-1 and -2 in 2018. See the history timeline.
Standards and references
- ISO 19650-1:2018 — Organization and digitization of information about buildings and civil engineering works, including building information modelling (BIM) — Information management using building information modelling — Part 1: Concepts and principles. ISO, 2018. Clause 3 (terms and definitions); Introduction.Original VDC Stack.io wording, based on the standard
Supports: BIM as use of a shared digital representation of a built asset to support decisions; BIM within information management · Status: Stage 90.92 (to be revised). Revision ISO/DIS 19650-1 at stage 40.93 on 2026-08-18 (decision for new DIS ballot). - ERIC ED113833 — An Outline of the Building Description System (Research Report No. 50). Institute of Physical Planning, Carnegie-Mellon University, 1974.Historical record
Supports: 1974 Building Description System as an early computable building description · Status: Eastman, C. et al. September 1974. - doi:10.1016/0926-5805(92)90014-B — Modelling multiple views on buildings. Elsevier — Automation in Construction, 1992.Historical record
Supports: 1992 academic use of "building information model" · Status: van Nederveen, G.A. and Tolman, F.P. Automation in Construction 1(3), 215–224. - Building information modeling — History. Wikipedia.Historical record
Supports: Locating primary sources for early-2000s popularisation (2002 vendor white paper; Laiserin commentary)
VDC Stack.io writes its own explanations and does not reproduce copyrighted standards text. Consult the cited standard for normative wording.
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VDC Stack.io. (2026). Building information modelling (BIM). In VDC Stack.io Knowledge Dictionary. Retrieved from https://vdcstack.io/dictionary/building-information-modelling/