If you’re an avid reader of our blog (which we hope you are), then you will have come across the terms Building Information Modelling (BIM) and Computer Aided Design (CAD). We talk about both of them a lot. But what is the difference between them, and why is it essential that construction managers know? Well, while the terms are definitely interconnected, there are differences between them, and they seem to be heading in different directions at the moment. For those who work in the construction business, therefore, it is important to know what the differences are in order to make more informed choices on your building projects.


Let’s start with good old CAD. Computer aided design is the process of using computers to help with the design process of a building, allowing CAD designers to create higher-quality drawings more quickly. CAD basically replaces the traditional hand drafting processes with an automated one.

Now let’s look at the new boy on the block: BIM. The NBS define BIM as “a process for creating and managing information on a construction project across the project lifecycle.” What this means is that building information modelling is basically software which applies typical CAD concepts to designing buildings in a way which includes both the physical and intrinsic building properties.

What are BIM and CAD Used for?

CAD has traditionally been used in the construction industry for the creation of two-dimensional designs, especially ones that require multiple components to fit together into a more substantial assembly, such as plant rooms.

CAD has rapidly been overtaken by BIM though, as BIM offers real-time visualisation and model-analysis that is better suited to the construction industry. The use of BIM allows architects, contractors and engineers to work together throughout the project using the same database and building model. It goes way beyond a CAD system, as it can show critical facilities management systems such as electrical containment and mechanical cooling systems as well as roofs and windows. All of this information allows everyone involved in the project to be able to closely analyse the building at every step of the way, even before actual construction has started.

The Future for CAD and BIM

We predict that in the future, the areas of CAD and BIM will continue to run alongside each other, with more developments happening as the world of construction becomes more and more advanced and specialised. As we have seen already, BIM will continue to grow and develop the more it is used to the point where CAD designers will no longer need to draft the building. Instead, they will just tell their software what the optimal footprint is and what load capacity is needed, and the system will do the rest. This will make the design process much shorter, meaning that more time can be spent on the actual build.

Keep following our blog or social media accounts for more updates on BIM and CAD, or alternatively, you can call us today to ask us about our services on 0161 427 0348.