What is BIM? Understanding the foundations

BIM is frequently misunderstood.

It’s often described simply as a 3D model or associated with a particular software package. Neither description is good enough.

At its core, BIM is about the creation, management and use of reliable information about built assets.

It brings together people, processes, information and technology to support better decision-making throughout the lifecycle of an asset.

In the UK and internationally, BIM is increasingly understood within the wider context of information management.

This reflects an important development in industry thinking: the greatest value does not come from creating a 3D model alone. It comes from ensuring that the right information is created, shared, managed and used by the right people at the right time.

BIM therefore applies not only to buildings, but also to infrastructure assets and systems, including roads, railways, bridges, tunnels, airports, water networks and energy infrastructure.

BIM is more than a 3D model

A 3D model can be an important part of BIM, but a 3D model by itself is not necessarily BIM.

Traditional computer-aided design (CAD) commonly represents an asset through lines, shapes and drawings.

BIM, by contrast, can represent elements of the built asset as information-rich objects and information containers.

For example, a wall, bridge component, pipe, pump or structural element can be associated with information relating to its geometry, location, specification, performance, classification, construction or operational requirements.

The value of BIM lies in connecting this information with the processes through which an asset is designed, constructed, operated and maintained.

A BIM approach may therefore include a wide range of information, such as:

• geometrical models;
• drawings and specifications;
• asset and product information;
• schedules and construction programmes;
• quantities and cost information;
• performance and environmental information;
• health and safety information;
• inspection and maintenance records; and
• operational and asset-management information.

As such, BIM shouldn't be understood as a single model, database or software platform.

It's a way of structuring and managing information to support the delivery and operation of built assets.

Why did BIM emerge?

BIM developed from the evolution of several areas of technology and practice, including:

• manual technical drawing;
• CAD;
• 3D modelling;
• object-based and parametric modelling;
• databases and information management;
• interoperability between digital systems; and
• collaborative working.

For many years, construction and infrastructure projects relied primarily on separate paper drawings and documents.

The introduction of CAD improved the efficiency of producing and revising drawings, but it didn't necessarily solve the wider problem of managing information between different disciplines and organisations.

A tool for collaboration

Modern construction and infrastructure projects are highly complex.

Architects, civil and structural engineers, building services engineers, contractors, specialist suppliers, manufacturers, operators and clients may all produce and use information about the same asset.

When information is created and exchanged through disconnected documents and systems, several problems can arise. These may include:

• inconsistent information;
• errors and omissions;
• coordination problems between disciplines;
• duplication of work;
• late discovery of conflicts;
• rework during construction;
• delays and additional costs; and
• poor transfer of information from project delivery into asset operation.

BIM emerged as a response to these challenges. Its purpose is to improve the way information is generated, coordinated, exchanged and used.

The central principle is that better information can support better decisions.

What are the benefits of BIM?

When BIM and information management are implemented effectively, they can support benefits for different participants across the built environment.

For clients and asset owners

Potential benefits include:

• improved decision-making;
• clearer information requirements;
• improved visibility of asset information;
• better understanding of whole-life requirements;
• reduced uncertainty and risk; and
• improved support for asset operation and maintenance.

For designers and engineers

BIM can support:

• improved coordination between disciplines;
• more efficient information production;
• improved visualisation and communication;
• analysis and performance assessment;
• improved management of design changes; and
• more reliable information exchange.

For contractors and specialist suppliers

Potential benefits include:

• improved coordination before construction;
• earlier identification of potential conflicts;
• improved construction planning;
• support for manufacturing and off-site construction;
• improved quantity and information management; and
• more efficient communication with the wider project team.

For operators

Structured and reliable information can support:

• operation and maintenance;
• asset information management;
• inspection and renewal planning;
• future modifications; and
• improved understanding of asset performance.

It's important to recognise, however, that BIM doesn't guarantee these benefits automatically.

Benefits are achieved through effective implementation, clearly defined information requirements and the appropriate use of information to support decisions.

BIM is not software

Perhaps the most important point is that BIM is not a particular software package.

Many different technologies can support BIM, including:

• modelling software;
• CAD applications;
• analysis software;
• geographic information systems (GIS);
• project and asset information systems;
• scheduling tools;
• cost-management systems;
• Common Data Environments; and
• asset-management platforms.

Technology is important, but purchasing BIM software does not, by itself, create a BIM process.

Similarly, an organisation can possess sophisticated technology but still experience poor information management.

Successful BIM requires an appropriate combination of people, processes, information and technology.

All four elements are necessary.

BIM and the future of the built environment

The development of BIM represents part of a wider transformation in the construction and infrastructure industries.

Built assets are becoming increasingly connected to wider systems and networks.

Infrastructure must be considered not only as individual projects, but also in relation to the services, communities and systems that it supports.

At the same time, the industry is increasingly concerned with whole-life value, carbon performance, resilience, sustainability and the long-term operation of assets.

These challenges require better information and better decision-making.

BIM provides an important foundation for this transformation by establishing more structured and collaborative approaches to information management.

But BIM should not be seen as the final destination of digital transformation.

It's one part of a broader movement towards improved information management, digital engineering, automation, connected data and new approaches such as digital twins.

Ultimately, BIM is about a simple but powerful principle: better information can lead to better decisions, and better decisions can lead to better outcomes for our built environment.