This 'paper' discusses how you might go about choosing CAD software if you were an architect or building designer in Australia.

Background

There are a considerable number of different CAD software programs on the Australian market – AutoCAD, AutoCAD LT, IntelliCAD (an AutoCAD clone at an affordable price), GardenCAD, Caddsman,  Design Cad 3D, Turbo CAD, Quikdraw, Catia, Solidworks, IronCAD, MicroStation, MiniCAD, Foresight, LisCAD, WESCOM to name just a few. Many of these are generic in the sense that the drafting tools contained within them can be used for in many different disciplines, including architecture and building.

There are also a number specialty architectural and building CAD programs - some of these are 'add-ons' to the above CAD 'engines', while others are stand alone products. Examples of software of this type are: KarelCAD, DRCAuto, AutoPLAN, SmartArchitect, SIACAD and ArchiCAD, Form Z, etc.

  These add-on architectural CAD packages are sometimes sold by the developer to another company. When this happens, there is often a change of  name - AutoPLAN is, we believe, in this category, and has been sold to a Canadian firm and renamed.

Autodesk (the makers of AutoCAD) also produce two of its own architectural products - REVIT and AutoCAD Architect, but they use the AutoCAD engine. By that we mean that the underlying program is AutoCAD which you use to place lines, circles etc. but when it comes to (say) inserting a window in a wall and automatically cutting the wall as you do so, these add on program do just that. [The base CAD program can also do it, you just have to learn how - so we do not think that the extra expense incurred in buying these add-ons is justified].

  There is a strong possibility that only one of these (REVIT and Auto Architect) will survive in the market place.

An example

A set of 2D plans for a simple dwelling created using AutoCAD LT 2005. No add on tools were used, just the base program itself. These are plans in what is called model space. Paper space (or layout) is used when a 'proper' printed set of plans is required.

The same drawing in IntelliCAD. Although IntelliCAD will open most AutoCAD drawings without difficulty, you should not take it as axiomatic that this will always occur perfectly.

The very same set of plans can be viewed from above if the external walls are extruded. This can be done in AutoCAD LT (light) or IntelliCAD. No special 'add on' architectural software is required.

Pricing

Prices of CAD software suitable for architectural use vary from less than $A500 to greater than $A10,000 per seat. Note that price is not necessarily a guide to features in the software or ease of use. This of course does not include the cost of the computer or ancillary equipment such as large format plotter/printers. You should really factor in buying at least an A2 size printer.

Strengths and weaknesses of CAD software

The CAD software programs listed above all have various strengths and weaknesses. Perhaps the most important thing to note is that design drawing data is saved in different file formats, variously called .DWG, .DGN, .CTA etc. This means that moving data from one CAD program to another is often not a trivial task. So, if your firm needs to accept data from or moves drawing data to other firms, an overriding factor may be file compatibility with others in your particular 'supply' chain.

Making the choice

In selecting CAD software, our advice is to firstly define where your organization sits in the ‘flow of information’ for the design work that you carry out. This will be different for each business. A firm of mechanical engineers who manufacture their own products that they design and develop ‘in-house’, can choose any CAD program that suits their needs, they don’t care what others are using as long as the software they choose suits their staff and the job is done efficiently.

However, architects and building designers, by the very nature of their profession, must recognize that they are invariably dealing with drawing files that come from other design professionals CAD software (surveyors, civil engineers, manufacturers of building materials etc.). Thus there is a need to consider not only their own requirements, but it is crucial to be aware of the CAD software that others that you work with are using.

Drawing exchange - DXF

Vendors of some of the CAD software listed above will tell you that they have included an export function to create what is called a Drawing Exchange Format (DXF) file which makes drawing translation a simple task. Be aware however that the translators providing for the generation (and importation) of DXF files are not perfect and do not deliver seamless translation.

As an example, most CAD programs do not understand entities called polylines which are used by IntelliCAD and AutoCAD. These get converted into short line segments as the DXF file is generated. Flexibility of editing in a subsequent drawing session in the 'receiving' environment is then compromised.

This drawing file incompatibility issue is not a trivial concern. We have experience in a job where profitability was severely compromised because (as we discovered at a very late stage) the survey software used for the base drawing (which in fact was WESCOM) uses AutoCAD text shape files to place tree symbols – letters appeared in the AutoCAD drawings where we expected to see existing trees. Many hours were lost on this project.

Drawing exchange - DWG

Many CAD software vendors are now members of the OpenDWG foundation and can offer very good ability to open AutoCAD/IntelliCAD DWG files as well as their own native format. Note that they will always be slightly behind the corresponding AutoCAD format. Autodesk keep changing their file format to limit compatibility with other vendors. There is no guarantee that DWG conversion will work flawlessly.

Your needs vs. the needs of others

There may be tension between your needs and those of others in the supply chain. On the one hand, you may want the ability to implement 3D rendering, to output rendered images in a format suitable for a commercial printer, the capability to paste aerial photographs as a backdrop to your drawings and the ability to smoothly work with multiple views of drawing files which might be greater than 10 Mb in size (in a  design for a wetland or large scale retirement village for instance).

MicroStation software from Bentley Systems certainly meets these criteria far better than does AutoCAD/IntelliCAD. However, in many states of Australia MicroStation has less than 10% of the market share (in Western Australia MicroStation holds >50% of the market) so you might eliminate MicroStation from your list of potential CAD programs because it is unlikely to be used in your supply chain.

So, the first step in choosing CAD software for architects/builders is to look at the local market and then at your own supply chain.

In Southern Australia there is no question that IntelliCAD/AutoCAD dominates the market. Our guess is that >80% of CAD files are created in the format used by IntelliCAD and AutoCAD (.DWG) in these states.

Recommendation 1.

This leads to the inescapable conclusion that the first piece of software purchased for CAD evaluation for a building design/architectural office operating in Australia should be IntelliCAD ($A 385.00). A second choice would be AutoCAD or AutoCAD LT (approx $2200).

A CAD standards system

It is important that your company defines a drafting standard at a very early stage.

Recommendation 2.

Publish a CAD standards manual for your organization as evidence that you have logically thought through the choice of CAD software.

Will it be AutoCAD, AutoCAD light or IntelliCAD or an 'add-on' to these?

Having established that the .DWG format used by AutoCAD will be the office standard, a choice then has to be made between the full AutoCAD (at $AUD6000.00) and AutoCAD LT (at $AUD2100.00) or IntelliCAD ($AUD 350.00)? The possibility of using an architectural 'add-on' needs to be considered.

Now it is time to look at your own specific requirements more closely. Which version of AutoCAD or IntelliCAD will do the job for you? The list of questions below (in no particular order of importance) should assist in decision making.

Image files: Is there an absolute requirement for pasting carefully registered scanned images into drawings? In AutoCAD 14 and later versions, images can be placed in drawing files, but, like xREFs, they are not actually part of the drawing file. The image is linked to the drawing file through a path name or a data management document ID. Linked image paths can be changed or removed at any time. By attaching images using linked image paths, you can place images in your drawing, only slightly increasing the drawing file size.

Early versions of AutoCAD LT did not have the ability to load this type of composite drawing, but LT 2000 now does. If you need this feature, then perhaps you can get an associate company with a full AutoCAD 14 or later to create the base drawing with its attached image files and then use LT 2005 for your design work. LT can handle pasting GIF, JPEG and PCX files into a drawing, but it may not give you the degree of control that you are after.

   It pays to keep checking on the features in the current version of AutoCAD LT, it tends to leapfrog the full AutoCAD. The development of IntelliCAD is also remarkable, check our web site from time to time. IntelliCAD 4 is now available.

Programming: 

AutoCAD LT is not programmable. Ask yourself "Do you have a requirement for using any of the programming languages that come with the full AutoCAD (AutoLISP, VBA, ARX etc.)? If you choose LT then you cannot run (say) a program to read a data file of points and create a (rectangular) surface mesh with facets to give you the surface topography of a site including contours. In the same way, you cannot use AutoLISP to create a new command to enable you to audit a finished drawing against a project or company standard (we have an example VERIFY). the VERIFY command checks fonts and blocks used, layer names etc.

The ‘Pack and Go’ feature of AutoCAD 14 and later is a great feature where project files are being exchanged, but relies on AutoLISP being present in your CAD program. This can only occur in IntelliCAD or the full version of AutoCAD.

3D Design:

Do you need to work in 3D? You may like to, but have you got the skills now? AutoCAD LT can read and display drawing files with 3D information in them, but it cannot create some very complex 3D shapes. Can you create and manipulate these complex 3D shapes in the full AutoCAD now, or is it a pipe dream?

Rendering: 

AutoCAD LT does not allow rendering (creating photo realistic 3D images with light sources with (say) a sky with clouds as a background. Before you say 'yes I must have this feature', are you willing to spend the time to learn to draw in 3D? It is not a skill quickly acquired. Is there and alternative? Can you learn to use your digital camera more effectively and then use PhotoShop to dress up images, pasting them back into AutoCAD for final presentation. Maybe you can learn to build simple 3D geometry as a wire frame image and then 'dress it up' using Photoshop.

Specific architectural CAD software

As mentioned, quite specific architectural CAD software is available. An example is SIACAD architectural toolbox which adds to IntelliCAD. An example is shown in the figure below.

As you can see, a custom menu has been added to the standard IntelliCAD drop-down menus. These have been organised in a manner to suit architectural drafting.

The figure below shows the operation of one of the tools in the menu above.

If 3D modelling is required, purchase a copy of a program such as SketchUp software and learn to import your CAD drawings for rendering, animations and fly through.

The above discussion illustrated the use of basic CAD software (IntelliCAD) with an add-on (SIACAD).

You should certainly spend some time evaluating a full architectural CAD software suite - ArchiCAD, REVIT etc., but be aware of the cost, not only of the software, but also the training and on-going support charges.

CAD Training: 

We are of course biased, but once you have chosen and installed your software, we believe that you need to employ staff who can use it effectively. We offer a pathway to CAD competence. Please click her to visit our broadband learning site.

Visit our courses pages for more information. Our courses feature flexible delivery - you can work at your own pace.

Final recommendation:

Purchase one (1) copy of IntelliCAD standard. Develop a CAD standards manual, train at least one 'in-house' drafter to use the software in its standard form to produce a full set of working drawings that meets your standard. Develop a set of block libraries for your use. Collect libraries from manufacturers of building materials.

Then, investigate one of the add-ons to IntelliCAD (such as SIACAD).

Install and use it only if your 'in-house' drafter supports its use.