What Is Computer-Aided Design (CAD) Software? Use Cases, Pros And Cons

Since its arrival in the mid-1960s, Computer-Aided Design (CAD) software has become an indispensable tool for architects and engineers, used to create detailed, digital 2D drawings or 3D models of construction projects.

However, contrary to popular belief, CAD offers more than just impressive visuals, as you will find out by reading this article.

At SFG20, the industry standard for building maintenance specification, we're committed to empowering you with the tools and knowledge you need to achieve building safety and facilities excellence.

If you’re considering adding CAD to your toolbox, read on to understand the applications, pros and cons, alongside how CAD differs from its close counterpart BIM (Building Information Modelling) and more.

What Is Computer-Aided Design (CAD), And What Is It Used For?

As a top-level definition, CAD relates to the process of using software to generate a digital representation of real-world objects that can then be used to produce a hard copy version.

For example, product designers utilise Computer-Aided Design software to create digital representations of drawings which can then be used for the manufacturing of everything from aeroplanes to mobile phones.

In the construction industry, CAD software is used to create 2D drawings or 3D models of building components or entire structures

It’s important to note that some CAD software operates solely in 2D, while others work in 3D or are able to convert 2D drawings.

In facilities management, CAD drawings play a crucial role in understanding where all of your assets are in relation to each other.

If you do not know where specific assets are, it can be difficult to operate and maintain them.

CAD drawings can also help with space planning, geo-locating and spatially managing assets as well as compliance documentation.

When integrated with Planned Preventative Maintenance (PPM) schedules, CAD layouts enable facility managers to visualise equipment locations, track maintenance zones and ensure all assets meet statutory inspection requirements.

A Brief History Of CAD And How It Has Changed

• The concept of CAD initially emerged in 1957 with the arrival of PRONTO (Program for Numerical Tooling Operations), which was invented by Patrick Hanratty.
• Before PRONTO’s arrival, technical drawings were produced by hand using large drawing boards, paper, rulers, pens and pencils. If an error was made in the drawing, it meant that it had to be produced again from the start.
• PRONTO was the world’s first commercial numerical control (NC) programming system, designed to automate manufacturing processes by converting instructions into machine-readable commands. PRONTO was marked as a significant milestone in Computer-Aided Manufacturing, laying the foundation for CAD.
• By the 1960s, Ivan Sutherland’s Sketchpad computer program had arrived, which enabled users to use a light pen on a screen to draft up designs.
• Two decades later in the 1980s, the first CAD software with 2D design, followed by parametric 3D design, was introduced.
• Eventually, CAD became more accessible and affordable, and advanced enough to be used in engineering applications. It then went on to become immensely popular in the construction industry.

Today, CAD continues to evolve, integrating with Building Information Modelling (BIM), Geographic Information Systems (GIS), and maintenance management platforms. This evolution supports a seamless flow of data, from design and construction through to facilities management.

Who Is CAD Used By?

Architects

Architects are among the most common users of CAD, employing it to create detailed 2D drawings and 3D models of buildings, design floor plans and elevation to help visualise concepts for clients.

Fundamentally, CAD technology allows architects to communicate their ideas more effectively and make rapid design iterations.

Engineers

Engineers use CAD software to provide the geometric basis of all separate building elements, and use further software packages to calculate load distributions, analyse stress levels and design critical structural components such as beams, columns and trusses, as well as pipe and cable sizing.

CAD also enables engineers to evaluate a building's structural integrity against various environmental factors and potential risks to ensure safety and compliance. It can also help to ensure that the building services are optimised for the building user’s requirements.

Construction Managers

Construction managers utilise CAD for project planning involving construction sequences, logistic laydown and site movement.

This information can then be used through additional software to undertake scheduling, cost estimation and resource allocation.

CAD software allows construction managers to visualise the construction process, track progress and monitor costs more effectively, leading to better project management and reduced delays.

It also allows construction managers to record any deviation from the planned design to easily create "As Built" drawings that provide a digital record of the built assets.

Facilities Managers

In the lifecycle of built assets, it’s Facility Managers who will derive the greatest benefit during the “in-use” phase of an asset’s life.

Facilities managers use CAD drawings to map and manage building assets across multiple locations. The challenge is ensuring the accuracy of the drawings and whether they are up to date and truly reflect what is physically present.

The drawings that are created to support the design process may go through many iterations before the final design is handed to the Contractor to build.

There may be reasons why the design cannot be delivered as envisaged, and the “For Construction” drawings are not an accurate reflection of what was built.

FMs should receive a set of “As Built” drawings that reflect any modifications or amendments that occurred during construction. These “As Built” drawings should be available for review during the handover of the building (RIBA Stage 6)

Over the life of a building, it will likely evolve and assets will need to be replaced.

A FM needs to amend the drawings if they carry out the work or for it to be contracted out to the parties involved in any construction work during the life of the building in order to hold the latest up-to-date drawings relating to their assets.

Failure to hold the latest drawings (CAD files rather than “flat” pdf versions) can have health and safety implications, as well as potential cost implications.

Contractors/Trade staff may be given incorrect information relating to Building Safety information that could lead to an accident. If a third-party contractor cannot be given a CAD file to update, they may have to charge for the complete reproduction of a set of drawings to be completed, as drawings are essential for both the Health and Safety File (H&S File) and the O&M Manual.

The drawings serve different purposes though: the H&S File uses drawings to show residual risks, locations of hazards (such as asbestos, buried services), and key safety features for future maintenance.

O&M Manuals use drawings (such as "as-built" drawings) to detail how to operate and maintain systems, with the H&S File often referencing or containing key safety-relevant drawings from the O&M documentation.

Essentially, drawings are the visual backbone for conveying critical health and safety information throughout a building's life cycle.

Integrating CAD with CAFM systems allows them to link physical equipment layouts with maintenance tasks, enabling faster response times with clear visual verification of compliance activities.

For example, FMs can click on an air-handling unit in a CAD floor plan and access its maintenance history and inspection dates and more, all in one interface.

What Are The Advantages Of CAD?

Accurate Design and Visualisation

CAD allows for the creation of intricate 2D drawings and 3D models of buildings, their structures and all the building elements including the services before construction begins, reducing the likelihood of errors and misunderstandings.

For more complex designs, CAD can help to optimise space utilisation and ensure consistency between digital records and on-site conditions. In facilities management, these accurate visualisations are invaluable for overlaying real-world data (e.g. asset IDs, mechanical layouts, maintenance zones).

Saves Time

Rather than manually drafting designs, CAD has made the design process far quicker and easier.

More specifically, one of CAD’s key benefits is its ability to duplicate and modify designs with ease, eliminating the need to create entirely new drawings by hand.

This feature also allows users to track and compare previous iterations of a design, making it easier to refine and optimise projects over time.

Beyond design, software packages that can be linked to CAD can automatically generate detailed reports and other essential documentation which can also reduce errors and in turn save time.

For example, these reports can provide information on the size and quantity of different types of spaces or even assets, automating the production of Room Data Sheets (RDS), or providing ‘take offs’ for creation of scope of works, specifications and cost calculations

However, this requires the CAD drawings to be correctly formatted. This means that standards need to be set, owned and managed.

Cost Savings

CAD eliminates the need for physical prototypes, minimises material wastage and allows for virtual testing and simulation, which can save organisations a significant amount of money.

From an operational standpoint, CAD-enabled facilities management reduces unnecessary call-outs and improves asset lifespan.

Plus, thanks to the precision and accuracy of CAD, this can minimise errors in design, leading to fewer costly mistakes and rework during production.

Communication and Collaboration

During the design and planning stages, CAD enables engineers and architects to visually represent their concepts and clearly communicate architectural intent to clients and stakeholders.

When combined with maintenance data, CAD becomes a live communication tool between designers, contractors, and facilities managers. For example, maintenance engineers can annotate drawings with real-world updates or compliance notes. This creates a continuous feedback loop between on-site and digital documentation.

CAD designs can also be easily shared among project stakeholders including contractors, subcontractors and general contractors for real-time collaboration and reviews of design changes.

What Are The Disadvantages of CAD?

High Initial Costs

Purchasing or subscribing to CAD software can be expensive, making it a considerable investment for smaller businesses.

Another cost to factor in is additional analysis packages, which can quickly add to the base price.

Another financial challenge to consider is that CAD software also needs to be regularly maintained and upgraded which can rack up in costs over time.

Requires Training And Specialised Knowledge

CAD software often has complex interfaces and functionalities, requiring extensive training and practice to take full advantage of it.

To use the software effectively, teams will need specialised knowledge and skills.

Examples of the competencies required can be found through the National Occupational Standards.

Dependence on Technology

Like any software, CAD isn’t 100% infallible. There may be instances of technical failures or crashes, which can disrupt the design process and potentially lead to delays and data loss.

In the event of this happening, this can not only take up a lot of time to recover the data, but it can also be costly.

There’s also the risk of intellectual property theft if there aren’t adequate cybersecurity measures in place.

What Is The Difference Between CAD and BIM?

As CAD is an umbrella term for design processes involving software, it’s often mistaken for being the same as Building Information Modelling (BIM). However, BIM takes the visualisation produced in CAD software and layers it with a rich array of further information.

Fundamentally, BIM is a methodology for undertaking Information Management of a building in a visual environment. BIM software provides a centralised digital platform to store, manage and access all data related to a building's design, construction and maintenance.

Although CAD doesn't offer the same level of data extensiveness as BIM, it’s an invaluable tool for the precise creation of floor plans, elevations and sections. For many facilities managers, CAD serves as the starting point before transitioning to or integrating with BIM.

Tool Up With These Additional Resources

CAD is an integral part of the design and documentation process, enabling engineers, architects and construction managers to bring design creations to life with both precision and speed.

However, depending on the complexity and scope of the project, integrating CAD with other advancing technologies like BIM can offer even greater benefits.

At SFG20, we want to help you make smarter, more informed decisions to help you prioritise building safety and compliance. Read on below with our BIM guide, or download our Ultimate Guide to FM Software. 

Read More