We don't always throw around the word "revolutionary," but building information modeling (BIM) has truly been that over the last few decades.
At its core, BIM represents an all-encompassing strategy for creating and managing information about a built or managed asset. It's a virtual representation that combines structured, multidisciplinary data to develop an intelligent model representing an asset throughout its lifecycle.
Now, navigating the realm of BIM can be overwhelming, especially when we start bringing in the concept of BIM dimensions.
If you're perplexed with all things BIM, we'll help demystify the concept of BIM dimensions and give you the knowledge you need to discuss BIM uses effectively.
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In concept, a BIM dimension refers to the different uses for a BIM process. Each dimension adds a layer of thought to the process for a particular use. These dimensions enrich the BIM data set and make it more useful to various stakeholders throughout an asset’s lifecycle.
BIM is all about creating and managing the information of built or natural assets. Just like an actual building has multiple layers, components, and dimensions, a BIM model also has multiple layers of information—which can be defined by a different BIM dimension, whether it be the components that we can physically see (e.g., walls, floors, etc.) or information like schedule, cost, and operations.
The construction industry is full of nuances and complexities; BIM dimensions are no exception. While there is generally industry-wide consensus on 3D and 4D (real dimensions in the scientific sense), and unless we’re talking about Superstring Theory, 5D BIM is generally understood to refer to the addition of cost, the acceptance and usage of further dimensions is a topic of ongoing debate worldwide.
Instead of diving deep into the definitions of specific codified dimensions, some leading global BIM experts prefer a shift toward plain language. According to Casey Rutland, Founding Director of digitalgreen.io and Chair of buildingSMART United Kingdom & Ireland, the reason is rooted in communication and acceptance.
“There's an easier way to communicate with people,” he explains. When it comes to BIM adoption, we, as an industry, tend to generate our own language. And the more we use our own ‘BIM language’ to describe things, the more we alienate people and turn them off.”
Casey and many leading global BIM experts believe we, as an industry, should use plain language to ultimately address the challenges we solve. “Let's just use plain language when we describe use cases for BIM rather than assign an arbitrary number the person we’re communicating with needs to unpack,” he says. “This goes beyond national preferences and would engage and inspire a greater number of people in our industry globally.”
Using use cases over dimensions could help avoid miscommunication and time explaining various dimensions to project stakeholders. “I would like to get to the point where we're just talking about the use cases for BIM. Whether it’s a rail line, factory, hospital, or school, there are both use cases similar in all of them or use cases specific to a particular project type. We’re trying to increase the use of the data created through a BIM process and engage a wider group of stakeholders, and there are potentially thousands of different use cases.”
To help industry professionals have meaningful, plain language discussions around data, Casey suggests referring to the buildingSMART International Use Case Management Service (UCMS). Developed by industry practitioners worldwide, this database enables stakeholders to exchange best practices and experiences for use cases across various sectors. Overall, the UCMS aims to establish universal language and definitions for describing and cataloging use cases based on ISO standards that are common across many project types.
While many BIM experts agree with the shift to more plain language when it comes to BIM, there is still generally worldwide consensus on 3D, 4D, and 5D BIM.
Below, we outline some of the most referred-to BIM dimensions and note some of the most significant differences across the industry. Let's look at each of these dimensions more closely.
3D is the most common use of BIM, and it represents the basic structure of a project. Think of it as the much more evolved version of the 2D drawing; while drawings consist of an X and Y-axis, 3D BIM adds another dimension: the Z-axis.
Essentially, 3D BIM lets you create and visualize the project’s design. It includes the geometry, such as beams, walls, floors, mechanical equipment, and other built elements, as well as their physical properties like materials and finishes.
One of the simplest uses of 3D BIM is its role in clash detection. Rather than manually reviewing drawings for design conflicts, teams can implement clash detection tools to automatically identify and resolve potential clashes, which saves both time and money during any phase of the project.
4D BIM adds the dimension of time to the 3D BIM model. It overlays scheduling information into the model, allowing users to visualize the construction sequence and plan aspects of the project more effectively.
When the project timeline is linked to the model, you can envision how the building will be constructed and evolve. You'll be able to see when different components will come together, which reduces risk to your projects.
On the project management side, 4D BIM is also practical for project managers because it makes it easy to plan and manage the construction schedule more effectively. Viewing the construction timeline in the context of the 3D model lets project managers spot scheduling issues and overlaps.
5D BIM incorporates estimating and cost data into the model. With 5D BIM, you can also clearly view cost-related information.
5D BIM is a powerful tool for budget management and cost analysis. It enables teams to add cost data into almost every aspect of the model to better understand how much a project will cost.
With 5D BIM, you can automatically calculate costs based on the materials, labor, and other resources associated with the elements of the 3D model. This saves time, optimizes resource allocation, and helps reduce cost overruns.
With a lack of international consensus beyond 5D, here are some of the most common use cases discussed.
This is often referenced when environmental data is integrated into the model.
This use case related to sustainability helps you optimize the project’s environmental performance. It can consider the project’s entire lifecycle and could include data like energy consumption and environmental impact.
A range of sustainability data, including energy usage, air quality, embodied carbon calculations, water usage, lifecycle carbon analysis, and much more, can be instrumental during the design and planning stage. It helps teams evaluate different design options and identify the most sustainable approach to building the structure.
Beyond that, this BIM use also plays a role during operations and maintenance; it streamlines asset management by including detailed information about the building's components, such as expected lifespan, maintenance schedules, and replacement costs. This, in turn, aids teams with managing energy systems, HVAC, lighting, and other elements that can impact the building's environmental footprint.
This typically represents operational and facility management and maintenance. It layers asset status, warranty info, technical specifications, and operating manuals into the dataset. This collection of uses helps you plan, schedule, predict, and optimize maintenance tasks throughout the building's lifecycle.
Contractors and subcontractors can list key building components and equipment with this BIM dimension, including replacement parts and specifications.
You can also leverage the data for predictive maintenance. With the right facility data at your fingertips, you'll be able to identify potential issues before they occur and be proactive with maintenance.
BIM is an effective tool for keeping a structure in top shape. It reduces issues, lowers costs, and minimizes disruptions to the building's operations.
These use cases refer to the overlay of health, safety, and welfare considerations into the BIM process. It includes all possible construction site elements—equipment, signage, machinery, scaffolding, etc.- and safety concerns during operation.
While international consensus has yet to be reached, it has been proven that BIM use in the context of health and safety data has the potential to vastly improve the safety of jobsites. Teams can leverage it to identify potential safety hazards and ensure compliance with health and safety regulations.
Health and safety data can be used to simulate construction processes in a virtual environment when assessing the safety of workers on-site. With the right data, this level of information can streamline the implementation of safety measures to reduce incidents.
Applying lean construction information to project data can eliminate inefficiency and waste in construction projects, using lean principles like value stream mapping.
More and more companies are looking for more ways to bring productivity into their workflows through industrialization. Introducing industrialized construction and design for manufacturing and assembly (DFMA) processes into a BIM environment can enable off-site construction methods and prefabrication with digital models.
The world of BIM dimensions is complicated, as evidenced by the need for more agreement on terminology across the industry. There is a need to shift towards plain language, focusing on use cases rather than numerically assigned dimensions. Given this fact, some industry experts prefer using “extended BIM (xD BIM)” when referring to dimensions beyond 5D. The idea of xD BIM is similar to focusing on use cases rather than prescriptive dimensions.
"Implementing BIM goes beyond simply accessing models; it's about unlocking the full potential of information,” says Ariel Castillo, Innovation Director, Miller-Davis Company. “However, it's not about following a sequential implementation of BIM dimensions; instead, it's about strategically identifying which uses can improve collaboration and elevate the project's bottom line."
The shift from using divisive terminology, such as 6D, 7D, and 8D BIM, to a more holistic approach, like use cases, can provide greater flexibility in exploring the vast amount of information and insights that BIM unlocks. Ultimately, this can enable project teams to concentrate on extracting more value and achieving better project outcomes by leveraging BIM as a powerful tool.
As more technology enters the market and new use cases for BIM are discovered, the potential of getting more value from data in the construction lifecycle continues to grow.
But what exactly does the future of BIM look like, and where can architecture, engineering, construction, and operational (AECO) professionals benefit the most?
At Autodesk, we believe that BIM is about improving everyone's access. While the technology certainly has many benefits for design teams, it can also be a powerful tool for those in the field and the boardroom.
Equipping your field teams with advanced BIM tools enhances data transparency and promotes team collaboration. That way, everyone stays aligned throughout the entire project—and beyond.
Want to learn more? Discover how Autodesk helps teams implement BIM in the field.
