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CAD: What Is It, and Why Should I Care?

Computer-Aided-Design Is Here to Stay


If you’ve spent any time searching for house plans, you’ve probably seen reference to “CAD,” “CAD Files,” “CAD Package,” or something similar in addition to regular “printed set” packages for the houses you’ve been interested in purchasing. You've probably also seen that CAD files are the most expensive plan package for any given house. What is CAD and why would you buy it instead of hard-copy printed plan sets?

For hundreds – even thousands – of years, homes and other buildings were built using hand-drawn plans, or blueprints, as they came to be known in the mid-nineteenth to mid-twentieth centuries. That's because of their blue background and white printing or white background and blue printing. These printed “plan sets” showed all the details a builder would need to build a structure.

Isn’t that all you need to have a house built? Technically, yes. But issues arise when you want to make changes to the stock – or pre-designed – plans you want to purchase. Depending on the extent of the changes, they may be either impractical to be made to printed plan sets or extremely expensive, dissolving one of the key advantages of buying pre-designed stock plans. That’s where CAD files come in.

Modern Farmhouse in white with covered front porch and 3 forward-facing gables

This Modern Farmhouse with 4 bedrooms, 4 bathrooms, and 2 half baths has been designed and rendered in CAD to create a home that has been virtually and painstakingly built piece-by-piece for streamlined modification and a realistic look (Plan 206-1028).


What is CAD?

A digital technology widely used in the architecture, engineering, and product design industries, computer-aided design (CAD) is a creative design process that uses computers and software instead of pen or pencil and paper for a wide range of projects. CAD helps to create designs in either 2D or 3D and to modify, analyze, and enhance drawings and other elements. The CAD software makes it possible to build an entire model in an imaginary space – allowing visualization of height, width, distance, material, or color before the model is used for a particular application.”

This software, which replaces drafting by hand with an automated process, is widely used by professionals in fields that require very precise technical drawings.

In the 1960s, CAD software was introduced to help architects save time in creating and modifying their drawings. While working for General Electric, Patrick Hanratty developed a program that used interactive graphics and a numerical control programming system. In 1963, Ivan Sutherland, an electrical engineer who has been called the “father of computer graphics” broke new ground in 3D computer modeling and visual simulation. The program called “Sketchpad” let designers “use a light pen to create engineering drawings directly on a CRT.”

Six decades later, the digital technology has been developed further to improve design quality and be used to produce 2D and 3D drawings and video animations. It has also become a core part of the design and architecture curriculum. 

Output drawing of a staircase created in AutoCAD

This detail of a staircase was drafted during a project using AutoCAD software (image credit: Detail Autocad by Mtpanchal under license CC BY-SA 4.0).


Is CAD everything that it's touted to be?

Let's focus on this important industry within the technology world, its advantages and drawbacks, and whether potential homeowners should buy their dream home construction package in a CAD file.    

There are four main professional sectors that rely on CAD.


1.  Architecture

The earliest examples of buildings, temples, and palaces in ancient civilizations have shown that architecture is one of the most demanding and precise disciplines. Even during those eras, drawings were used to develop and convey a design idea into a coherent whole.

The advantage of contemporary times in the age of technology is that strict disciplines like architecture can use software support to tie in and enhance all the elements involved in the project design. Today, large companies can rely on entire suites of advanced modeling software to create and manipulate their designs, and smaller companies can combine different individual tools for their work.

With CAD programs like AutoCAD, Sketchup, and Chifel Architect, architects and house designers can virtually "build" structures, ensuring that various parts of the building will actually function and work together as designed. They can visualize aspects of the structure in ways there were imposible with pen and paper and create "finished buildings" that can be manipulated – and even be toured in a virtual video.

One of the most important aspects of CAD for homeowners interested in purchasing house plans to build their dream home is the cost-effectiveness of being able to make even major changes in a house's design and size. Because all of the elements to build the house have been painstakingly entered into the software during the design process and manipulating those elements is less time-consuming than creating them in the first place (or re-creating them in the case of changes), modifications can be made more economically. Also, by purchasing the CAD file of a home instead of printed plan sets, you can hire local architects, designers, and/or engineers to work on your plan for modification and permitting purposes, streamlining the difficult process of actually getting your house built.

Floor plan of 1438-sq.-ft. Contemporary style home showing finished living areas in brown

Here is a computer-aided design of the layout of a one-story, 1,438-square-foot Contemporary style home with three bedrooms and two baths. The floor plan indicates all the rooms, amenities, and other features of the home (Plan #193-1140).



2.  Product Design

In this discipline, industrial designers use CAD software to visualize an object and to understand and confirm how it will function.


3.  Graphic Design

Graphic design professionals also use 2D or 3D CAD software to create visualizations in print, video, and computer imagery. With this software, designers can add effects, typography, shapes, and backgrounds to improve their visuals.


4. Engineering

CAD programs used by engineers are as many and diverse as the existing engineering fields. Some of the most common programs focus on infrastructure, buildings, circuits, telecommunications networks, thermodynamics, mechanical parts, medical devices, and manufacturing.

Engineer designing a component in CAD

This engineer is using an advanced CAD program to design part of the headlight of an electric scooter (photo by Kumpan Eelectric on Unsplash).


Benefits of CAD

Computer-aided design is sometimes described as essentially a complex digital version of manual drawing,” with the accuracy of even the most experienced manual drafters. 

Here are several benefits – other than accuracy – that make CAD attractive to several industries: 

1. Time efficient because of the use of computers instead of hand drawings

2. Ability to create and visualize 3D models – and videos – from 2Ds and make as many changes as needed with less effort than hand drawing.

3. Easy to learn and use for professionals who need it (architects, engineers, product designers, and those who have a background in design).

4. The ability to make copies of designs quickly and share them with various departments is a huge advantage over manual drafting. Intricately connected to this is worldwide sharing of files among different companies – a definite plus in the global economy. While CAD files can be shared, viewed, and modified all within a single program, manual drawings must be scanned and may need multiple programs for recipients to open, view, and give comments on the designs.

5.  Modifications are easy to do, tracked and saved in the file. This reduces the risk of losing or forgetting modifications.

6.  Permission controls restrict access to CAD files – making them more secure than paper drawings. The controls are helpful for security purposes and prevent unauthorized people from editing the files – something that is difficult to do with paper drawings.

7.  Computer-aided design files are easy to save and store for future use and reference, and for editing and printing.

8.  Require less space and can be stored in the computer’s hard drive.

This Modern Farmhouse style home has been designed in CAD, which allows it to be manipulated digitally to create a "fly-around" video of just about every aspect of its design as if it were actually built and filmed (Plan #207-1003).


Disadvantages of CAD

As much as computer-aided design has been a useful tool for architects, house design professionals, and engineers, there are also a few drawbacks. 

1.  The major drawback is the high cost of software packages – worsened by the fact that this is a recurring expense since software and/or operating systems need to be updated on a regular basis. In addition, training in how to use the software, and design tools like graphic tablets can also be expensive. For homeowners, this translates into a premium product that costs more than other forms of house plans.

2.  It is time consuming to train the staff who will operate or run the software.

3.  Work can be lost or “hacked” when computers breakdown. Work can also be affected by computer “viruses.

4.  Lack of individual or distinctive style that is present in a manual drawing.

5.  As technology and computers take over, there will be less employment opportunities in the design industries.


Traditional Hand-Drawn Architecture – Obsolete?

Traditional hand-drawn architecture has a long, storied past. Have you ever looked at ancient historical buildings and thought about who came up with the conceptual designs and how resources were brought together to construct these amazing wonders? Were there actual drawings and plans for the Roman Colosseum, the Greek Parthenon, and the Egyptian Pyramids?  

History tells us that architectural drawings date back to the earliest civilizations. In fact, archaeological findings from the Egyptian and Mesopotamian eras revealed   ground plans of buildings with detailed descriptive specifications, dimensions, and even full-scale mock-up models. These ground plans, diagrams, and hand sketches were working drawings for the construction process and accurately resembled the finished building.   

As we moved through centuries of civilization – from ancient Greece and Rome to the Medieval and Renaissance periods, to the minimalist orientation of Modernism, and Contemporary times – the art of architectural drawing became more widespread, refined, and improved.

It was just a matter of time before technology would enter the picture and make an impact on the architectural landscape.   

Since computer-aided design was introduced in the 1960s – and now elevated to a sophisticated digital technology – the prestige of hand drawing has been under siege –  but not enough to make it irrelevant in the 21st century.

While almost all homes today are designed and drawn in CAD, there is no reason why it cannot co-exist with hand drawing. In fact, a survey of readers conducted by ArchDaily revealed that almost all seemed to believe that CAD and hand drawing form an ideal equation – with sketching a tool for forming ideas, and design software for the precision and clarity that is required at the later stages of the project. 

So even in a highly technological era, original and distinctive sketches still play an equal role in the design process.  


Computer-aided design has affected the home design industry. Thanks to digital technology, architects and designers can create innovative new features, 3D modeling, walk-throughs and much more – and still stamp their distinct and defining styles on their projects.


Footnote: The lead image of this article shows high-definition renderings of homes, clockwise from top left: a one-story, 1900-square-foot modern Farmhouse with the two bedrooms and two baths (Plan #100-1357); a one-story transitional Farmhouse style home with thre bedrooms and 2.5 baths (Plan #142-1180); a beautiful Contemporary style Craftsman Ranch, with two to four bedrooms, two to four bathrooms, and one to two half baths, depending on whether you finish the basement or not (Plan #161-1133).



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