The adoption of BIM methodology in engineering and architecture firms is bringing about an unprecedented revolution. Not even the shift brought about by the use of CAD software to create project drawings is comparable.
There are already many countries where its use is recommended or required by the government. In Spain, for example, the use of BIM has been mandatory in public construction tenders since December 2018, and it will become mandatory for civil engineering projects as of July 26, 2019. That is why companies are taking steps to implement it.
Therefore, once the company implements the new methodology, engineers in the construction sector will need to have the necessary training for this new way of working.
How do CAD and BIM differ?
Below, we’ll explain the main differences between carrying out a project using CAD or BIM software, to help you understand the full implications of this change in the industry.
1. Software and a methodology
When we talk about CAD, the first thing that comes to mind is that we’re talking about computer-aided design software. BIM, on the other hand, isn’t just software we can use to design our projects—it encompasses much more than that.
Building Information Modeling should be understood as a work methodology that, in addition to serving as a tool capable of creating three-dimensional representations of a construction project, can also manage construction schedules, analyze project costs, and assess sustainability, among other things. That is where the main difference between CAD and BIM lies.
2. Work Method
As we explained in the previous section, the introduction of BIM has radically changed the way civil engineering and architectural projects are carried out. This new methodology allows everyone involved to work on the same model, something that was not possible with CAD.
This means that communication is much more seamless among the various parties involved in the project, since the different engineering teams (structural, mechanical, electrical, etc.), as well as the construction companies and material suppliers, all work within the same environment.
Furthermore, one benefit of everyone working on the same model is the ability to correct errors that, in the case of CAD, would not have been caught until the construction phase. This occurs, for example, when a wall and a pipe occupy the same space—a situation that would have been very difficult to notice in CAD drawings.
3. Information Management
An engineering project generates a vast amount of data as it progresses. Therefore, it is necessary to maintain meticulous records to ensure that no information is lost along the way.
In this regard, the way we manage the documents produced is completely different depending on whether we are working in CAD or BIM. In the former case, the bulk of the files created consists of drawings that are independent of one another.
In BIM, on the other hand, everything that is generated can be easily managed using databases within the model itself. This makes it easier to share documentation among team members and ensures more efficient information management.
4. Inspection and Maintenance Throughout the Service Life
Another difference between CAD and BIM is the management of a building throughout its lifecycle. The BIM methodology allows for monitoring during the operational phase using the same model that was used for the design and construction phases, whereas this is not possible with CAD.
5. Software Used
Finally, let’s talk about the different software programs used in each of these fields. Naturally, since CAD and BIM offer different functionalities, the software used also differs. The software with the largest market share for computer-aided drafting is AutoCAD, while Revit, ArchiCAD, and Allplan are the most commonly used programs for BIM.
In addition, it is important to discuss interoperability between programs in BIM. This concept refers to the ability to transfer data generated by one software tool to another, which significantly streamlines operations within the environment. One example is Presto’s Cost-It software, used for quantity takeoffs, which is integrated into Revit via a plugin.
In short, there are many differences between CAD and BIM, which is precisely why a major update is necessary. For this reason, both companies and engineers must adapt to this new way of working. What are you waiting for to get up to speed with BIM?
