CAD Drawing: Why We Use CAD

What is CAD?

CAD, or computer aided design refers to software used by architects, engineers and draftsmen to produce a wide range of plans from floor plans to structural plans and even mechanical system plans for HVAC (heating ventilation and air conditioning).

The capabilities of CAD are nearly limitless, the programs of today provide more than just 2D lines, shapes and colours. CAD has evolved into 3D providing all industry users a full view of their drawing and it includes graphic visibility of materials, heights, accurate shadows and shadow diagrams calculated by manually entering a location and time.

Clearly, this is a time benefit as well as a cost saving for all architectural and engineering firms. The ever evolving industry is now able to provide square metre and even cubic metre measurements, how amazing is that? Crazy to think that some still design solely with pencil and paper!

The software today has allowed the role of draftsmen and building designers to evolve and provide services that architects do, you can read more about that on our previous post, Draftsman VS Architect.

History of CAD

Dr. Patrick J. Hanratty and Dr Ivan Sutherland are the two most recognized pioneers of the industry both having a large involvement in the beginning and evolution of CAD.

“Sketchpad” was developed by Dr Ivan Sutherland for his thesis at the Massachusetts Institute of Technology in 1963. It consisted of tools that we use today including the duplication of a line, zooming in and out and line tools for corners and curves.

“Pronto” was developed by Dr. Patrick J. Hanratty “the Father of CAD” as a program for numerical tooling operations, allowing programmers to produce the tool movements for machining parts.

The commercial application of these programs was for electrical, automotive and aerospace industries.

Pros of CAD

Faster service provided to you

Using CAD software to draw and design your project, we definitely save time. It is estimated that hand drawing could take nearly triple the time to prepare a project.

In the building design industry there are plenty of scenarios where our clients are in a rush, some being the arrival of a new family member or baby! This can be an extremely stressful and busy time, the last thing you need is your plans to be delayed.

Neater drawings

Designing a home requires a lot of thought and time, presentation shouldn’t be hard too, but it was before CAD. Many things happened to the plans of those in the hand drawing days, from papers being torn by a sharp pencil or ruined by knocking a glass that spilled everywhere, plans were destroyed in seconds.

When copies were required the originals were traced and this also ruined the presentation and accuracy of drawings. There are so many details on a plan and having the ability to edit, delete or move them without any smudging or tearing is phenomenal.

Saves costs due to time

Seeing as it would take triple the time to have a project drawn up, you would be charged accordingly. The largest expense is labour and that would be incurred at a greater rate if you had to have your plans manually drawn up, reviewed and edited time and time again.

This cost saving is great because we can provide a service at a reasonable rate to produce a drawing easily and comfortably. Due to this, more thought and innovation can be applied to a project. Thanks again CAD!

Prepares accurate plans to scale

Plans required by council for development application such as shadow diagrams are automatically produced when a time and location setting is entered (depending on the software). This can save designers a large amount of time as well as the room for error manual calculations can create.

Realistic design approach

The 3D CAD or BIM (building information modelling) software available today allows for a unique design and a realistic perspective of the building. A building can be viewed in relation to the site, adjoining dwellings and landscape to determine whether or not the proposal is aesthetically pleasing.

How do you know if you really like your house until you see it in real life? Many people can not even tell the difference between a professionally rendered 3D and a real life photo, that is how high the quality of graphics and 3D software is today.

3D design goes beyond exterior and interior perspectives, a “walk-through” video can also be created by the software. This is a real life experience of walking through your new home, granny flat, duplex or renovation.

Cons of CAD


Some say the “limitations” of a program can affect the creativity of the designer. I personally do not agree, however, if those who feel limited need to they can always prepare sketches by hand and produce them on the computer later.

Other limitations such as unusual representations of a building (or even an unusual building) are a specialized niche where a professional is required and they can be hard to find.

Unreasonable drawing

This means that many architects, building designers and draftsmen rely solely on the software to create plans and drawings without knowing what they mean or how the building is put together.

Plans should not be heavily detailed unless there is a specific join or construction of a component because a builder is the one who chooses how to put a building together.

Expensive software

Although CAD software has not evolved so greatly since it’s beginnings, it is still considered very expensive. Whether a firm is using 2D/3D CAD or BIM, the price remains high. This often includes yearly subscription payments and limited licensing.

Many free/cheaper programs are out there but are not capable of producing the entire package required for a formal application.

Costly, time consuming training

A firm that believes in great presentation has standards in place. These may include fonts for certain areas, hatch patterns, line colours, RL level symbols etc. Creating a dedicated standard format for all projects is a time consuming factor with CAD software.

Training is a separate matter. The software may not be extremely complex however proper use and documentation needs to be done a certain way. If a project is not documented correctly issues may arise later.