Last edited 11 Apr 2024

BIM dimensions, maturity and levels of development

1 What is building information modelling?
2 How is building information modelling defined?
3 BIM dimensions, BIM levels of development and BIM maturity levels
4 BIM dimensions 2D-7D
5 Unoffical BIM dimensions 8D onward
6 BIM levels of development (BIM LOD)
7 BIM maturity levels
8 Related articles on Designing Buildings

[edit] What is building information modelling?

Building Information Modelling (BIM) is a very broad term that describes the process for specifying, creating, and managing digital information about a built asset such as a building, bridge, highway or tunnel.

Fundamentally, the purpose of BIM is to ensure that appropriate information is created in a suitable format at the right time so that better decisions can be made throughout the design, construction and operation of built assets. It is not about creating a 3D model on its own or an add-on to the model, it is a fundamentally different way of running a project from the early stages through to occupation, maximising digital capabilities. The amount of data associated with the model is referred to as the dimension or sometimes level when referring to complexity or capabilities.

[edit] How is building information modelling defined?

ISO 19650:2019 defines BIM as the: 'Use of a shared digital representation of a built asset to facilitate design, constructionand operation processes to form a reliable basis for decisions.'

Transforming Infrastructure Performance: Roadmap to 2030, Published by the Infrastructure and Projects Authority 13 September 2021, defines BIM as: ‘…a combination of process, standards and technology through which it is possible to generate, visualise, exchange, assure and subsequently use and re-use information, including data, to form a trustworthy foundation for decision-making to the benefit of all those involved in any part of an asset’s lifecycle. This includes inception, capital phase procurement and delivery, asset and facility management, maintenance, refurbishment, and ultimately an asset’s disposal or re-use.’

[edit] BIM dimensions, BIM levels of development and BIM maturity levels

BIM dimensions refers to the level of information that is stored alongside or integrated within the modelling environment. In general these accepted BIM dimensions include: 3D, 4D, 5D, 6D, 7D, there are also potentially 8D, 9D, 10D and 11D, though these are not generally formalised or standardised and as such recognized as known dimensions.

BIM levels of development (LOD) refers to the degree of accuracy, intricacy or granularity of the model or design. In general these LODs include LOD 100, LOD 200, LOD 300, LOD 400 and LOD 500.

BIM maturity levels refers to the extent to which project partners are collaborating with BIM. In general these matirity levels run from BIM level 1 through to BIM level 6.

Whilst all three terms used to decribe the capabilities and capacities of a BIM model describe slightly different aspects, they do also crossover in terms of their meaning, in as much as 8D BIM describes similar capabilities as LOD500 as there is a greater level of detail, and the greater the level of detail the more likely it is that collaboration will be higher in maturity.

[edit] BIM dimensions 2D-7D

2D BIM is a basic digital geometric model on the X and a Y axis with associated further information. Today it is not industry standard, and often not considered as a BIM tool but it is still used.
3D BIM describes employment of basic geometrical and graphical information, essentially on the X, Y and Z axis associated with further associated information. This allows 2D information or drawings to be produced with associated information, generated from cuts through the 3D model. Multiple models of component parts can be created to generate a whole model, whereby clash detection tools help highlight incongruencies.
4D BIM includes the element of time, with the ability to sequence the construction, which can help design and construction teams in planning and the client in visualising the stages of construction. 4D BIM can also help in better collaboration between the design and construction teams leading to increased maturity levels in terms of collaboration. It can also give the possibilitiy to produce 2D diagrams to help communicate and manage the construction process, along with some costings in terms of Gantt charts or timelines.
5D BIM stats to include (to varying degrees) construction quantities and cost information thus allowing better costing estimates and in turn the promise of better cost management. It is important to establish the basis and responsibility of the cost information within the project set-up, such as establishing if costs are pre-tender estimates or a record of as-built costs, what methods are used and if operational costs are included.
6D BIM is by some considered to be adding facility management information set, by others this is 7D BIM and 6D BIM is sustainability impact data. So there isn't really an industry consensus regarding 6D, as such, if it is a target then it is wise to set out precisely the requirements and goals between all parties. This also includes establishing the longevity of any facilities management information and how much of the lifecycle of the building becomes part of the planning, the same applies in terms of sustainability.
7D BIM is by some considered to be adding sustainability impact data such as environmental, economic and social impacts, whilst by others this is the facility management information set (and vice versa). So there isn't really an industry consensus regarding 7 or 6D, as such, if it is a target then it is wise to set out precisely the requirements and goals between all parties. This also includes establishing the longevity of any facilities management information and how much of the lifecycle of the building becomes part of the planning, the same applies in terms of sustainability.

[edit] Unoffical BIM dimensions 8D onward

(8D BIM) is not nesesarily a fomalised BINM dimension and as such is here bracketed but in gerneral it concerns health and safety during design and construction. It is though, as with 6D and 7D not clealy established or formaisled in many casesa and should be carefully defined on a project by project basis in terms of data types, scope, units, measures and in the context of the most recent legislation, such as the Building Safety Act.
(9D BIM) in the UK 8D/9D BIM and onwards is less formalised or recoginsed but they are listed here for infornmation.- 9D is generally related to lean construction aiming to maximise productivity and minimise waste.
(10D BIM) indicatively focusses on the industrialisation of construction, aiming to increase efficiency and productivity through the use of off-site construction methods and prefabrication approaches.
(11D BIM, 12D BIM and onwards) there are various discussions on what the next stages of development of BIM might be, though these vary and might cover a refocuss on post-construction elements or deeper focus on sustainabuilty and social impact, but as the number of dimensions increases there may be tendency to look at other approaches or develop these as the industry develops, for example considering the rapid growrth and incorporation of AI into design and constriuction processes.

[edit] BIM levels of development (BIM LOD)

BIM LOD was first introduced by the American Institute of Architects (AIA) in 2008, it defined five levels of development to describe the level of detailing appropriate for early to later stages of a project. In the UK a similar approach might be considered as relating the BIM model to the stages of the RIBA plan of work. Fore further information visit the page overlays to the RIBA plan of work, in particular the BIM overlay.

LOD 100 describes concept design stages, essentially the equivalent of hand-sketched or, symbolic digital 2D representations of the design-build project.
LOD 200 describes the schematic design stage where a partially defined idea with approximate project sizing, form and building elements are established.
LOD 300 describes the detail stage of a project whereby a 3D digital model represents the building in terms of architectural design and engineering drawings with more exact localised dimensions and elements.
LOD 350 is essentially a halfway stage between detailing and fabrication, a point where tools suich as clash detection are employed to ensure individual elements are sychronised into the whole, resolving co-ordination issues and inconsistencies to produce a construction ready model.
LOD 400 is the last stage of modelling before fabrication and assembly. The model must contain an accurate representation of the elements, objects and thus building with finalised and defined elements, sizes, locations, connections, materials and so on.
LOD 500 represents the as-built final model of the building with supplementary information such as installation processes, installation dates, comments on issues, notes for the users and so on. It is an important element of the process when considering concepts such as the golden thread of information or how the model might used to inform Building Management Systems (BMS) and assist facilities management team after handover. Further tools available via COBie or the Soft Landings process can assist in this.

[edit] BIM maturity levels

BIM Level 0 describes essentially unmanaged computer aided design (CAD) including 2D drawings, and text with paper-based or electronic exchange of information but without common standards and processes. Essentially a digital drawing board, CAD drawings and little collaboration.
BIM Level 1 describes a form of managed CAD, with the increasing introduction of spatial coordination, standardised structures and formats as it moves towards Level 2 BIM. This may include 2D information and 3D information such as visualisations or concept development models. It might be described as 'Lonely BIM' as models are not shared between project team members and involves both 2D Drawings and 3D digital models.
BIM Level 2 becomes a managed 3D environment with data attached, but created in separate discipline-based models. These separate models are assembled to form a federated model, but do not lose their identity or integrity. Data may include construction sequencing (4D) and cost (5D) information. It might sometimes be referred to as 'pBIM' (proprietary BIM), with multiple 3D models for different project teams on a digital platform.
BIM Level 3 is a single collaborative, online, project model with construction sequencing (4D), cost (5D) and project lifecycle information (6D or 7D). This is sometimes referred to as 'iBIM' (integrated BIM) and is intended to deliver better business outcomes. It creates a single work flow shared 3D model environment for different project teams and disciplines.
BIM Level 4 is also a single collaborative, online, project model with further additional information regarding time and project management details. There is some inconsistency regarding the difference between BIM level 3 and BIM level 4 so it is important to establish definitions and targets at the start of the project.
BIM Level 5, is likewise a further developed, single collaborative, online, project model with further additional information for project management particularly regarding costs, budgets and scheduling.
BIM Level 6 adds yet further developed layers of information, including material quantities and other data that can be used in the assessment of sustainability impacts. It importantly remains a single collaborative, online, project model with the further additional information layered within the model and accessible by all project partners.