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BIM vs. CAD

By Microsol Resources | BIM, CAD

If you have any job that involves construction, you’re probably familiar with two terms: BIM and CAD. However, depending on what you do, you might not have had the chance to work with both methods. So even though you’re aware of their existence, it might be hard to explain the difference between the two.

For a long time, architects and engineers have relied on computer-aided design (CAD) programs to design their projects. And these programs work great — they allow the design of extremely detailed 2D and 3D models.

However, since building information modeling (BIM) appeared, many architecture and engineering firms readily embraced it. Others, though, are still reluctant and wondering if it’s possible to just convert CAD files to BIM. The short answer to their question is no. But that won’t resolve the confusion that seems to exist when it comes to CAD and BIM.

So, in this article, we’re going to tell you more about both CAD and BIM, and break down the differences between the two programs. Also, we will explain which one you should gravitate toward depending on the industry you’re in.

 

What Is CAD?

CAD refers to the use of computers in the creation, modification, or optimization of a design. It allows architects and engineers to create high-quality drawings for projects that require multiple parts to fit perfectly within a more complex construction project.

As we mentioned, CAD users can create 2D and 3D models of the parts they plan on building or making. What’s more, CAD makes it possible to review a construction before the production process begins. Due to its versatility, CAD is used across many industries — from architecture and design to mechanical, electrical, or civil engineering. In fact, 3D CAD software has redefined both the construction process and manufacturing over the past couple of decades, making production faster than ever before.

 

What Is BIM?

On the other hand, BIM is a method that uses some of the CAD concepts in building design. It allows designers to create detailed models for the entire lifecycle of a design process that include not just the physical but also the intrinsic properties of a building.

BIM is a relatively new methodology with which a team of engineers, architects, and contractors work together to design and build a building. And they can do that using the same database and in real-time, so communication is much easier. Similar to CAD, a team using BIM has the option of 3D visualization. Thus, the team can work out even the smallest details before the construction starts.

Apart from the 3D modeling, BIM technology has evolved to 4D, 5D, 6D, and 7D dimensions. Each dimension has its own purpose. For instance, as you already know, 3D BIM represents the three dimensions of a building. Then, 4D adds the element of time, 5D allows cost estimation and budget analysis, etc.

In short, we can summarize BIM as a digital representation of a real building. BIM software, Revit for example, can include all the functional systems, such as HVAC and the electrical system, as well as all the structural elements (walls, door, windows, etc.).

 

The History of CAD

Although its significance is clear to anyone who ever had a job in the construction industry, CAD’s origin is not as easy to pinpoint. To explain the beginnings of CAD, we have to go back to 1957. That is when Dr. Patrick Hanratty, now dubbed “father of CAD”, developed Pronto. Pronto was the first numerical-control programming system. Then, in 1960, an MIT student named Ivan Sutherland created Sketchpad, the first program that showed that it was possible to make technical drawings on a computer.

There is some debate as to which one is truly responsible for the creation of CAD, since Hanratty’s system is more of a CAM (computer-aided manufacturing) system. However, many experts agree that his invention was the one that led to CAD as we know it today. But Sutherland’s Sketchpad is also pretty significant. It allowed a designer to use a pen to draw on a monitor, which was extremely advanced at the time.

So, we believe it’s safe to say that both inventions were important contributions to CAD software, and in turn, to the industry as a whole. Over the last several decades, CAD has been constantly changing and improving. And with it, the industry was changing as well. For instance, its influence on aerospace technology alone is enough to see its significance, but it has truly advanced any manufacturing activity. Nowadays, it’s impossible to find an engineer that hasn’t used at least one CAD software. It’s basically become a job requirement. What’s more, with computer technology still constantly developing, it will be interesting to see what CAD will be like in the years to come.

 

The History of BIM

As for BIM, it has existed as a concept since the 1970s when the first software tools for modeling buildings appeared. However, these were expensive, so widespread use was not yet possible.

The term ‘building model’ was first used in a 1986 paper by Simon Ruffle. In the paper, Ruffle states that CAD systems have evolved enough to create models that “more closely represent the way buildings go together.”

The actual term ‘building information model’ first appeared in 1992., in a paper by G.A. van Nederveen and F.P. Tolman. But it wasn’t until 2002 that the acronym ‘BIM’ entered common use when Autodesk published a white paper titled “Building Information Modelling.”

Although it doesn’t have as long a history as CAD, BIM technology has been equally important in its own niche. BIM, in a way, was built with an architect in mind. Since it is focused on one industry, specifically on building projects, BIM can create advanced features that cater to architects and their entire team. The design process is now much easier than it was just ten or even five years ago. And just like CAD, BIM is always improving and we are excited to see how the future of architecture is going to be influenced by that.

 

What Is CAD Used For?

In general, engineers across multiple industries use CAD programs, such as mechanical and electronic engineering, plant design, and civil engineering. Its utility is best showcased by the fact that in CAD you can design a variety of products, from a toaster or a phone to an airplane.

CAD is especially useful for projects that involve multiple parts that are then connected into a larger unit. With CAD software, you can create 2D drawings and 3D models of all these parts, which makes the manufacturing process easier. Some of the more popular formats for 2D drawings are DXF and AutoCAD DWG. 3D formats that are the most prominent include Solidworks, Creo, and a couple of others. In addition, if you’re ever short on time, you can check out some websites that offer ready-made CAD models.

In the past 20 years, 3D CAD software has been in widespread use. It all began with manufacturers trying to adapt their production processes to more strict guidelines. They also wanted to improve the time it takes to create and manufacture a new product. Nowadays, CAD is a must for high-quality products to reach the market more quickly than ever.

 

What Is BIM Used For?

BIM’s main use, on the other hand, is in the design and construction of buildings. As such, it’s most valuable to architects. But architects don’t work alone. Architects, engineers, and contractors all use BIM in a collaborative effort to build a building through the same database.

The BIM tools make it possible for all the stakeholders to digitally adjust both the interior and the exterior parts of a building. In short, it allows you to take care of MEP engineering in just one program. That includes walls, doors, windows, but also plumbing, lighting, etc. And that is where BIM’s biggest advantage lies: interactivity. In BIM software, all the components of a building design are interconnected. That means that you can make any adjustments you need in a single edit, which makes project management much easier.

In comparison, if a design needs a change in CAD, all the layers affected by the change have to be adjusted individually. And if there are many layers to a design, making the adjustments is going to take a considerable amount of time. That means that BIM is more time-efficient, and, in turn, more cost-efficient.

Like with CAD, you can also find a ready-made BIM model online, if not to use them, at least to get some new ideas.

 

Which One Should You Use?

Well, as CAD is typically used in mechanical and electrical engineering, you’ll want to stick with it if you’re in one of these industries. That is where CAD works best, and there truly is no better option for designing multi-part assemblies.

BIM, on the other hand, can only be used in the design and construction of buildings. So, if that is what you do, we strongly recommend you opt for BIM. It is becoming the industry standard, and for a good reason.

But no matter which AEC industry you belong to, you should at least know the basics of both methods.

 

What Does the Future Hold For CAD and BIM?

Although even people in the industry sometimes mix the two types of programs up, we expect them to become increasingly different in the future as each becomes more specialized.

CAD hopes to evolve so that even smaller teams that don’t have a big budget can design virtual prototypes, perform fatigue tests, and other kinds of tests that used to require many people and a lot of work in the past.

Meanwhile, BIM will continue its development as a building model software. In the future, we expect that it will become even more optimized so that architects won’t have to manually draw much. All they’ll have to do is input some parameters, e.g. the load capacity the building should have, its optimal footprint, etc. A process that would normally take weeks will take just a couple of days. That will allow the firm to devote more time to the actual building.

 

Conclusion

Ultimately, whether you need BIM or CAD will depend on the individual project. 2D CAD software has become obsolete in recent years, and more and more construction managers turn to BIM methodology. However, CAD 3D models are not going anywhere and are only to become better. As you now know, CAD works across industries for both electrical and mechanical engineering projects. Meanwhile, BIM is a program for the design and construction of commercial buildings.

Thus, in the architecture domain, it’s safe to say that BIM is winning the BIM vs CAD  battle. And if you’re an architect or a part of construction management wondering if you should switch to BIM — you absolutely should. You’ll save time, money, and you’ll get better quality buildings. But in other industries, CAD is still the go-to for engineers and it seems like that won’t change soon.

Here at Microsol Resources, you will find support for anything related to CAD and BIM. Be it adapting to advanced workflow, implementing a new strategy, or tech issues, we’ve got you covered! Whichever building model you decide is best for your next project, we’ll help you execute your plan and achieve success.

INDUSTRIES: Architecture, Buildings, Civil Engineering, Civil Infrastructure, Construction, MEP Engineering, Structural Engineering

Published on August 1, 2021 in BIM, CAD.

About the Author

Microsol Resources delivers integrated solutions that help customers design, simulate and analyze their ideas, increase operational efficiencies and maximize their return on investment in their technology solutions.

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