Thinking about finally adding computer-aided design software to your workflow? Maybe you want to expand your existing CAD investment into facilities management, or what we now call BIM (Building Information Management) software.

In this two-part article, I'll explain some important questions you need to ask yourself and your CAD vendor or vendors before you buy.

Start by remembering that the design process is a thinking process. If your software gets in the way of your thinking, it may not be right for you.

That said, a CAD or facilities management package is nothing more than a database program with a very fancy interface. Each line in the drawing is nothing more than a multicolumn data entry. There are the coordinates (in 2D or 3D space) for the line's beginning and end. There's a mathematical formula that defines the shape of a curve -- a line that isn't straight -- and a notation of the curve's orientation in space.

Anything more is just embellishment. There might be data that tells the line it is part of a larger object. There can be data that defines the material the object is made out of, and what its weight, strength, surface finish, cost and other properties might be. That's what makes CAD software "Building Information Management" software. Once you design a building element in BIM, you can duplicate it throughout the structure. If you have to modify the object, you can allow the modification to propagate through your design automatically. That saves time and reduces errors.

1. How well can you draw with it?

Some designers like to rough out a sketch first. Some go right to hard-line drawings. Some work only in 2D; many younger designers only work in 3D. As I reviewed software for architects, I was amazed at the variations in technique I saw. You can download and try almost all packages these days. Narrow your choices by what feels right.

2. Does it fit your office needs?

You may practice out of multiple offices, require a mobile workstation, or need to accommodate client-side desires like 3D visualization and photorealistic rendering. Your practice may be in landscape design, HVAC, civil, or mechanical. Don't assume one package is the best for all.

3. Can you afford it (or find a way to afford it)?

Licensing terms vary and are often negotiable. Do you need a laptop install? Must you accommodate a colleague in another practice for a month? Or install software at the client's location during a build?

Remember, too, that the initial price you pay for the software and the equipment to run it is usually small compared to the overall cost over three to five years for updates, and equipment upgrades. Look for the right deals. I just updated the graphics card on my big server. The price was $30 for a perfectly suitable "48 core" [Intel processor] closeout that sold for $129 just a year ago. With a rebate, the final cost was ten bucks.

Although vendor support these days is good, you'll need to seek out more. Is there a local user group to join? Does the local university or community college offer courses in the package you are considering?

4. Can the new software add deliverables that you can upsell for new business?

Yes, the eventual owners might actually pay for a "building information management" package at the handover. Or they might simply make design with a BIM-capable software package a requirement, a box you have to check to get the business. Either way, you need to design with CAD software that that is compatible with what the client, or the client's client wants. Building owners and their tenants often use sophisticated facilities management software these days. Is your software compatible with what they use? Can you translate the entire "as-built" design into a separate file that can be read directly into FM, for an extra fee?

5. Compatibility?

As mentioned above, compatibility can be a deal-breaker. A good way to test different levels of compatibility: Move an existing file through a translation program for your client's current or proposed software. Then translate it back. Does it act the same? Often, the translation turns BIM "objects" back into dumb lines. Sometimes, it turns curves into a series of little straight lines that approximate the curve.

Part two of this CAD-buying series will discuss file security and other levels of compatibility, such as handling of materials vendors' symbols. It will appear in the next issue of ENR's FutureTech newsletter, which is delivered to your inbox every other week.

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Steve Ross has been using and reviewing CAD software since 1985. With degrees in physics and journalism, he has authored or edited 19 books, including one for ENR (Construction Disasters: Design Failures, Causes and Prevention, published in 1983). He has been honored by NSPE and by the New York State Society of Professional Engineers. You can write him directly at