2D to 3D Models: Entering the Third Dimension

March 14, 2018 Jean Thilmany

2d to 3d models

As you’ve likely heard or read, the construction industry is in a state of transformation: from flat to fat; from two to three dimensions.

Because of the benefits a third dimension brings, many industries that formerly relied on two-dimensional drawings, drafts, and designs have been moving into 3D visualisations. And construction is no different. After all, we live in a three-dimensional world and software and digital representations that mirror our world allow humans to better visualise buildings and designs before they are built.

Today, construction firms that solely use 2D representations are relying on outdated methods. The use of 3D models affects many aspects of a firm’s work and its relationship with clients, including project cost, communication, and bid creation. All of that has a significant impact on a project’s time and cost.

The benefits are so great that in a 2014 McGraw Hill Construction BIM study, 75 percent of contractors from around the world reported a positive ROI when they began using BIM. Meanwhile, a McKinsey report found that 75 percent of companies that have adopted BIM reported a positive return on investment with shorter project lifecycles and savings on paperwork and material costs.

Read on for a look at the way transitioning from 2D to 3D models will enhance projects and bring your construction firm up to speed while increasing productivity and building a better bottom line.

What Doesn’t Happen in 2D, Happens in 3D

At the most basic level, 2D representations don’t depict a project in a way humans intuitively make sense of the world around them. 2D drawings work to explain a concept; however, they don’t function like 3D models. When information is presented in only two dimensions, every person involved in the project forms his or her own idea of how the building or site will look when complete. They see it in their mind’s eye, not on the screen.

So, when the 3D capabilities introduced with BIM (Building Information Modelling) software came along, innovative AEC firms threw 2D models out the window. The 3D models from BIM look like the world around us. They’re relatable. With data embedded in the model, they add a dimension present in the world that can’t be achieved in 2D. This gives every stakeholder on the project a better, more natural, more intuitive way to understand its design.

BIM is now widely used by architects, civil engineers, structural engineers, and large contractors.

The use of 3D technology is now migrating down to small and mid-sized builders who continue to rely on 2D drawings due to the familiarity of this format... But the fact is, 2D drawings don’t play well—or at all, really— with the other systems used by a construction firm’s partners. The 2D CAD tools currently used in the construction industry create pictorial data with no data about the representation tied to it. The information can be used for little other than plotting a drawing.

By working with the 3D models, all project stakeholders have a common understanding of the project. Communication doesn’t get lost as models are continually translated back and forth from two dimensions to three. The construction firms that work with 2D models actually face more risk losing vital measurements and details as they translate the 3D plans they receive back into 2D.

Builders take the project from paper to real-life—they’re the ones who turn the flat designs into actual 3D (built) structures. If the end result doesn’t match what stakeholders have envisioned in their mind’s eye, builders take the blame.

For instance, BIM models immediately point out construction inconsistencies—designs that simply can’t be created in the real world and that, in 2D, often wouldn’t be discovered until construction began. Builders can analyse the BIM model to find things like “clashes” and can tilt, rotate, and manipulate them to provide various views of the model. When everything works on the 3D model as it should, it works in real life as well. No need for plan interpretation. Complex construction projects become easier, less prone to backups, equipment over or under orders, and structural do-overs. One step deeper is the new Hololens Hard Hat for construction workers, which uses mixed reality to superimpose the 3D model onto the real environment.

Construction firms have also found that 2D models don’t let them place every design aspect of a project into one design, which could include things like detailed floor plans, pipework, and electrical work. BIM models make this possible for an overall look at the project, and for an even closer look at potential clashes, errors, and design oversights.

BIM serves construction firms in another way as well: costing and timeline estimating. It allows all those involved in a construction project to build and maintain a digital 3D model that illustrates everything about the building, from its basic geometry to the model number of its connecting bolts. It offers businesses more information for estimating and bidding than they’d ever get from 2D models and allows them to more effectively schedule their projects.

Some types of 3D BIM models also simulate real-world conditions, so stakeholders can see how their builds will look in different light—depending on time of day or weather, for example—or at different stages of construction. That visualisation capability comes in handy during the bidding phase and when updating a client on construction milestones.


Building projects are more complex than they were in the past, when 2D models would suffice to serve as constructible models. Innovations such as solar panels, rooftop green spaces, and smart-building technologies, are included in new designs. Project stakeholders are often spread around the area, the country, or even the globe. And with tight construction profit margins, builders need to track their material and costs closer than ever.

Builders are turning to BIM because the 3D modelling system (the “M” in BIM) includes information (the “I” in BIM) that tracks expenses, automatically creates bills of material, and allows teams in disparate locations to work together inside the same design. The companies that took advantage of these features initially viewed them as extras or add-ons but now see them as vital to cutting project costs, increasing productivity, and ensuring projects finish on time.

BIM collaboration capabilities allow everyone involved in a project—including architects and even in some cases suppliers—stay updated on changes to the building design. Coordination is seamless and, as it’s done via the computer, certainly easier, and faster, to track than picking up the phone or emailing an architect. You can be certain everyone involved has seen design changes and that the changes were made to the most recent “working” copy of the model.

The models even include a step-by-step process for materials, crews, timelines, and processes for construction managers to follow and complete. Every step is documented and accessible.

So why haven’t all construction firms using the outdated 2D site models embraced the third dimension? It comes down to fear of change. Yes, the fear of change over the cost to change. The costs of bringing in BIM are quickly returned, as the studies cited above point out.

The costs of not moving to 3D are far greater for these firms than the remaining with 2D. Of course, change is scary. Embracing a new way of doing things takes a bit of time and can involve a learning curve. But not changing is not an option for builders that want to remain competitive.

The world has moved on from hand-drawn blueprints. The construction industry can move into the third dimension as well.


About the Author

Jean Thilmany

Jean Thilmany is a freelance writer in St. Paul. She writes about construction, engineering, and robotics issues and served was an editor at Mechanical Engineering Magazine for 15 years. Her work has appeared in a range of publications.

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