What is BIM (and how does it work)?

Posted on: 15 May, 2024

Here’s why building information modelling (BIM) is at the centre of digital transformation across architecture, construction and the wider built environment.


Construction projects are far from simple. From the design and planning of buildings to their physical construction and assembly, each stage of the building lifecycle consists of various processes, all involving the use of measurement, data, and decision-making. While a passer-by sees a building, a construction manager can see the thread of decisions, processes and information behind its creation.

Information is a crucial component of any construction project, and – as with any large and complex undertaking involving multiple stakeholders and disciplines – it needs to be recorded, stored and managed effectively. Historically, this information was stored and managed via physical blueprints, but thanks to the onset of digital transformation in the built environment, a new, digital alternative has emerged: building information modelling.

Learn more: Technology will define the future of sustainability

What is building information modelling?

Building information modelling (BIM) is a collaborative process for the creation, management and storage of information relating to a construction project. This framework allows planners, architects, engineers, developers and other industry professionals to collaborate in the planning, design, creation and operation of buildings or infrastructure.

A similar term, building information management, is often used interchangeably to refer to this process, and emphasises the importance of managing data as much as creating digital and 3D models.

How does BIM work?

In BIM, digital representations of physical environments and their functional characteristics are recreated through data. This digital representation is then populated with information and multi-disciplinary data from various sources, effectively acting as a central knowledge resource and a 3D, digital version of a traditional 2D set of blueprints.

BIM models are composed of BIM objects, which are 3D representations of individual objects and structures, each of which are populated with corresponding information. Its application impacts every aspect of the building lifecycle, from the planning and architectural design process to construction through to a project’s operational phase.

Why is BIM important?

The construction industry is under greater pressure than ever before to improve its efficiency. 11% of all global emissions are attributable to embodied carbon – the greenhouse gases that result from the construction of a building before it is put into operation.

Learn more: What is embodied carbon (and what can we do about it)?

BIM can help teams consolidate disparate data on sustainability to keep them in line with environmental reporting and performance requirements, and make important optimisation and tweaks that can have a significant impact on the embodied and operational emissions of a building. It can also streamline processes, drive efficiency and identify opportunities for cost savings.

What’s the difference between BIM and CAD?

Computer aided design (CAD) refers to software, rather than a process. Becoming mainstream in the 1990’s, CAD has continued to evolve, helping to usher in a new era of digital innovation in the built environment, but while there are similarities, it’s not the same as BIM.

BIM is primarily focused on the process of managing the information pertaining to the design, construction and performance of the building as a whole. These information types can vary from geometric/drawings/schedules to performance and maintenance metrics from a range of stakeholders and consultants. In contrast, CAD has more application in the design phase, often being used to create complex and detailed models of smaller components.

In essence, CAD software is used as a tool in the management and creation of information in the BIM process.

How BIM information shared?

To allow information to be accessed by different disciplines and stakeholders, project teams utilise common data environments (CDEs) – an online platform that acts as a single source of truth for the collection and dissemination of data on a project.

The different levels of BIM

As BIM is such a sophisticated process, its capabilities can be tailored to meet the demands of the project in question. As such, there are different levels of ‘maturity’ to BIM implementation that teams can work towards:

  • Level 0 – no collaboration: At this level, BIM has yet to be implemented, meaning teams are relying on paper and 2D drawings and may be utilising CAD software.
  • Level 1 – partial collaboration: Often termed ‘Lonely BIM’, this level involves partial collaboration, as structures are standardised, spaces are coordinated and 2D and 3D information is developed.
  • Level 2 – full collaboration: At this level teams are working in a managed 3D environment with data attached, but are using separate models based on their disciplines.
  • Level 3 – full integration: This level of BIM is still in the process of being defined, but strives to encourage deeper collaboration by enabling all stakeholders to work through the same integrated model.

Many definitions of BIM add further levels to this framework, adding layers to integrate external factors, from time and cost estimation to sustainability analysis and scheduling.

8 key benefits of incorporating BIM

BIM offers a wide range of benefits for construction teams, including:

1. Fosters collaboration

Building projects aren’t handled by lone teams and construction professionals – they require the cooperation of a range of functions, from contractors and engineers to architects and surveyors.

Rather than having all of these teams work in isolation, potentially creating waste, confusion and even contributing to project delays, BIM can unify all within one shared workspace. This can act as a single, integrated source of truth that everyone can access.

2. Increases efficiency and sustainability

With sustainability a central priority for modern construction businesses, every stage of the construction lifecycle presents an opportunity for improved efficiency and reduced emissions.

Construction teams can identify opportunities to improve a building’s sustainability credentials with BIM, from improving energy efficiency to allowing more natural lighting, identifying sustainable alternatives to materials like concrete and even employing lifecycle assessments that cover a building’s emissions over its entire lifespan.

Learn more: 12 sustainable alternatives to traditional concrete

3. Faster project turnaround

Delays are among the biggest pain points for construction project teams, and one that can be addressed through the use of BIM.

Integrating this technology can reduce the construction time of a project by identifying potential risks before they even occur. For instance, issues/overlaps on the construction site can be identified through running test scenarios, helping to minimise the risk for reworking and identify processes that can be improved.

4. Enables prefabrication

Another benefit of BIM is that it can enable construction firms to adopt prefabrication – the process of building parts of a project off site in a different location. Creating a visualisation that can be shared among teams means components can be prefabricated, which in turn can reduce construction time, ensure greater quality control and improve the sustainability of a project.

Learn more: A guide to prefabrication (and how it’s transforming construction)

5. Reduced project costs

From construction delays to resource wastage, changing client priorities and fluctuations in the market, the costs of a construction project can quickly and unexpectedly mount up. However, project teams can utilise BIM to keep costs to a minimum in several ways.

Through the use of digital technologies, site logistics can be optimised for the construction phase, allowing the potential of a space to be realised and ensuring smooth workflows, whilst simultaneously preventing delays or accidents. Similarly, BIM can be integrated into cost and waste management through need-based purchasing frameworks that can accurately predict what materials are actually needed for a project.

The cost saving potential for BIM doesn’t end once the building is completed – design teams can utilise thermal simulation, for example, during the design phase to identify optimal orientations, sizes and insulation levels to improve energy consumption.

6. Enhanced safety

The construction phase of a project is a hazardous one, fraught with risks of serious and even fatal injury. Addressing this is a key concern for construction firms, and alongside adopting new processes and ensuring they’re providing adequate personal protective equipment (PPE), making use of technology to minimise risks is crucial.

BIM can step and offer safety benefits before construction is even underway by identifying potential risks through visualisation and simulation.

7. Greater quality assurance

Along with reducing the risk of injury, BIM’s ability to visualise and simulate elements of a construction project can give teams greater control over the quality of the final product.

Being able to create visualisations and run simulations allows design teams and project managers to identify opportunities to both improve quality and minimise risk throughout the entire process before construction has even begun. By adopting this methodology, construction projects can adopt a proactive approach to quality assurance.

8. It supports facilities management

BIM’s role in the building lifecycle isn’t over once construction is complete. This tool can help businesses with facilities management – the effective management of buildings, grounds and infrastructure in a way that promotes comfort, safety and efficiency. Digital records gathered during the project’s construction can be used to help optimise the management of assets and space, as well as keeping on track of maintenance and evaluating its overall performance.

The disadvantages of BIM

While BIM is justifiably seen as representing the digital future of construction projects, this process isn’t without its limitations and drawbacks:

Investment will be needed to train staff

As an innovation that is still in the process of being adopted in the industry, many firms have a digital skills gap that they’ll need to fill if they want to realise BIM’s potential. Training staff to be able to utilise this software will require additional investment on top of the cost of the initial cost of the technology.

Substantial technological investment may be required

Then, of course, there’s the cost of the software itself. Not only will organisations have to review and potentially overhaul their existing technology suite, but they’ll also need to ensure their existing technology are powerful enough to handle this software. What’s more, while plenty of software is available for free, finding the tool that best fits both the need of one organisation and the needs of a project’s many stakeholders can be difficult.

Successful implementation requires buy-in

As with any technological innovative, a new process or piece of software can only be implemented effectively if the people using it buy in to its adoption. This is particularly true of BIM, which requires cooperation, trust, and an agreement to share data from multiple stakeholders in order for it to be successful. For some firms, this will require a significant cultural change.

Clients need to be engaged

Not only will other stakeholders and teams need to be engaged with this method of building information management, but the client has to be on board, too. The amount of cooperation and collaboration BIM requires, along with the time spent populating it with information will ultimately go to waste if the building owners, facilities managers and end users fail to recognise the value of the tool and utilise it during a building’s operation.

What does the future hold for BIM?

While BIM is still far from becoming mainstream in the construction industry, work is under way to usher in new updates and innovations to this technology. Even now, BIM is growing more and more sophisticated, as more levels of maturity are incorporated and industry professionals integrate 4D, 5D and even 6D modelling. At the same time, the rise of artificial intelligence (AI) and automation has opened up opportunities for teams to reap improved efficiency and even greater return on investment from this tool.

The extent of how much BIM will impact the building lifecycle and the construction process is yet to be fully realised, but as the built environment strives for a more efficient future, this innovative technology will likely play a pivotal role in the sustainable development in the coming years.

“It is widely recognised that built environment talent shortages over the next five to ten years will be caused by a shortage of digital and technology skills. Although a process, BIM requires those engaged in it to have a broad range of digital skills and behaviours so that suitable workflows can be established to overcome interoperability and coordination challenges.”

“With a multidisciplinary approach to BIM, the federation of data and information requires a workforce at the design, construction and operation phases of a project, that has the requisite digital literacies and skills to ensure the benefits of BIM are fully realised. Amongst many other attributes they possess, architectural technologists can be relied upon to support the execution of BIM in a project lifecycle due to their specialised skills in integrating design and construction processes through advanced digital tools. Their expertise in creating precise and detailed 3D models ensures accurate visualisation, clash detection, and seamless collaboration among stakeholders. By managing and coordinating the flow of information throughout the project, architectural technologists enhance efficiency, reduce errors, and facilitate informed decision-making, ultimately leading to successful project outcomes.”

“Now is a really exciting and rewarding time to be pursuing a career in architectural technology. If you want to be at the forefront of the built environment’s digital future, UCEM’s BSc (Hons) Architectural Design Technology will give you the technical expertise and literacy you need to become a sought after contributor to the sector.”

Marc Fleming MCIAT – Programme Leader BSc (Hons) Architectural Design Technology

Find out more: BSc (Hons) Architectural Design Technology – University College of Estate Management