By continuing to use the site you agree to our Privacy & Cookies policy



Why is it that complex decisions are rarely simple, while seemingly simple decisions are frequently more complex than they first appear? A question from George Scott of Levitt Bernstein is a perfect example of the latter. He asks (see letter overleaf) whether we think his office should transfer from using AutoCAD LT to ArchiCAD, and whether it would slow down production.

On the surface his dilemma emanates from pitting the world's biggest-selling two-dimensional drafting tool against a niche three-dimensional building integrated modelling (BIM) tool.

It may appear to be a simple question of 2D vs 3D but in reality the potential change is fundamental. The question here is not about the number of copies sold. It is about the type of tool and how that tool may impact upon or even necessitate a change in existing business process. This question is about traditional computer drafting vs integrated prototype modelling. The comparison is less David and Goliath and more chalk and cheese.

The practice currently uses Autodesk LT for all 2D drawing production. Often referred to as AutoCAD Light due to its 'reduced' levels of functionality, the new version of LT is a competent tool and, at about £700, is far better value than its 'loaded' AutoCAD stable-mate. However, casting value aside, even Autodesk recognises that LT is not the sharpest tool in the 2D drafting box. In a recent marketing release to resellers, Autodesk suggested that previous versions of LT required many 'tedious workarounds' to make each user productive.

This could explain why our reader described his experiences of LT as 'limited'. You may consider switching to a different 2D drafting tool altogether, such as PowerDraft or MicroStation from Bentley, but I suspect that is not an appealing option as it would involve the same investment required to upgrade to the latest versions of LT or AutoCAD for minimal improvements in functionality over the Autodesk applications.

The alternative option currently being reviewed is ArchiCAD. It is an 'almost' fully integrated 3D building modelling tool popular with relatively small numbers of professionals in this country. I admit that I think ArchiCAD is a cracking tool, but I still have reservations about its use for BIM.

As a 2D drafting tool ArchiCAD is much easier to use than LT for the drafting of 2D plans, sections and elevations, and is capable of producing sweet-looking drawings much faster, but in my opinion it lacks the 'I' in 'BIM' - ArchiCAD is not fully 'integrated'.

My biggest gripe with ArchiCAD is that it is not possible to take any building model and extract true, coordinated 2D views of plans, when there are more than two floor levels visible in the plan. Yes, you can 'work around' this issue, but in doing so, you lose the very coordination sought by an integrated solution and if George Scott was happy struggling with workarounds he would be happier with his existing Autodesk LT.

Perhaps this simple question should be broadened; perhaps this is not an ArchiCAD vs LT question after all. Scott would do well to take a wider look at the market and at his business process to understand better where he hopes to gain process and functionality improvements. Other BIM products on offer include Revit from Autodesk; All Plan from Nemetschek and the Building suite of products (Architecture, Structure, Civil & Mechanical & Electrical) range from MicroStation's developer, Bentley Systems.

A BIM approach could indeed deliver real process improvements to the practice, but such a change would (like the 2D upgrade route) require a big financial outlay in new software and training, and would for a short while involve a reduction in productivity following training. However, one may still decide that the initial investment is worth the longer-term gain. Some issues to consider when evaluating the Return on Investment (ROI) should include:

? recruitment;

? compatibility; and - results.

You should pay great attention to each of the above areas. Should you adopt a software application that is not widely used, then recruiting new staff could prove problematic and making a commitment to training all new staff would be an imperative. This would reduce the restrictive nature of less widely used tools when recruiting, although moving to a company that uses 'niche' software could be viewed as a career-limiting move by candidates who do not see their new job as a long-term prospect.

The second key area of evaluation should be compatibility. Pick a vendor that shares information about its file format openly so that at no time will you be locked into a technology that alienates you and your data in an industry that is increasingly sharing information to collaborate on projects, thus removing duplication, waste and errors. You need to be compatible with the rest of your peers.

Finally, select a tool that does what you need it to do.

Try hard not to be fooled by the bells and whistles that you are unlikely ever to use. That is like paying tax on income you have never earned!

With that in mind I would only really consider two BIM tools if the decision to go down the coordinated 3D route is taken;

I would evaluate Revit and the Bentley Building suite. I would look for open file formats, true integration across models and disciplines and a brand that appeals to respected companies and career-minded professionals alike. I would also look for a technology that enabled me to 'guide' my team through the transition with as little pain and upheaval as possible.

Finally, bear in mind that your IT manager may be resistant to change as their comfort zones may be threatened by the introduction of new software that they are not a whiz on. Work with them and make them a central part of the evaluation process.

If they are to support any new tools effectively they need to be trained up and be confident with them.

Let us know how you get on!

Have your say

You must sign in to make a comment.

The searchable digital buildings archive with drawings from more than 1,500 projects

AJ newsletters