Designing a 3-D World

By Stan Shook | Oct 15, 2009




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Building information modeling (BIM) is rapidly emerging as the standard coordination and design method of the future. It won’t be long before we look back and wonder how we survived without it. In the meantime, we need to figure out all that BIM is, how to use it and, perhaps most important, how much it costs.

First, you’re likely going to need AutoCAD MEP or similar software with BIM functionality. Figure at least $4,500-plus for that. You may also require an application that allows you to view and work with the models of other trades. Navisworks is one such program, and it ranges from $8,000–$14,000-plus.

Of course, these applications don’t run on any computer. You need a rocket ship loaded with 8 gigs of RAM, a quad-core processor and a serious graphics card or two. Add $4,000-plus. You will also want a really large, say, 42-inch, flat-screen monitor or a couple of 24s. Add $800-plus for that. You may even need an equally powerful laptop so your modeler can work on the job site; add another $4,000-plus.

Keep in mind the system I just described is for only one machine and for one user license. Your company may need more than a single BIM designer working at any time. It all depends on the job(s) you are modeling.

What do BIM designers cost?

Much will depend on whether you outsource this work or hire employees. Hiring a full-time BIM designer may carry the same salary of a normal CAD detailer. However, you really need someone who understands electrical installations and has training with BIM software. I would budget at least $50,000 per year in salary plus benefits. Add at least $5,000 per year for ongoing education, computer updates and technical support fees.

If outsourcing, be prepared to pay higher hourly rates than you would for a regular CAD designer. I have seen prices ranging from $75 to $125 per hour. It may seem expensive, but the cost should include the super computer, software and most management costs.

One key cost factor is finding a designer who knows how to design electrical work in 3-D, exactly as it will be installed. It requires a deep understanding of how conduits are routed, supported, what they look like, how/when they bend, junction boxes, cores, etc.

This will affect how much time and guidance the designer requires from your company’s more expensive senior personnel (e.g., foremen, supervisors, project managers). In my experience, contractors always fail to cover this very expensive cost factor in their estimates. No matter whom you hire, you will need to manage and coordinate with him or her daily until the BIM stage of the project is complete.

Your modeler also must constantly interact with modelers from other trades. So he or she must be capable of intelligently discussing changes and conflicts and making key decisions without help. He or she also will need to attend weekly “clash detection” meetings. These meetings can consume hours, even entire days.

For the project you are bidding today, you need to find out what the project specifications say and/or what the contract requires. What elements of the electrical and communication systems will your company be required to model? Will it be everything or just “major installations”?

We are currently modeling a large, $5 million-plus electrical county courthouse. Only major systems are being modeled. “Major” means any conduit larger than 2 inches, all cable trays, conduit racking and seismic bracing, large junction boxes and any other major electrical installation or equipment that might conflict with something else above the ceiling or in a certain area of the building. Whew!

Wait! There’s more. We also modeled any below-ceiling installation that penetrates into the above-ceiling real estate, such as recessed lighting fixtures, speakers and even four-square boxes. We also had to model all conduit installations in-slab and below-ground on the site. So, when the specifications say “major systems only,” you could be required to model all site duct banks.

Looking at the contract

There is a strong possibility that usage of your modeler will be required during the entire length of the contract, depending on the size and type of project. A simple office tenant improvement with very few major systems may only require a month’s worth of modeling, that is unless every single device, outlet box, conduit run and lighting fixture has to be modeled. A major facility, such as a hospital, with a two-year contract, could require the same amount of “full-time” modeling and possibly a team of two or more modelers.

I recommend seriously looking at your specifications and contract. Discuss any possible BIM requirements with the architect, general contractor or project manager prior to bidding the job. Are they going to require you to buy and use software you do not yet own or know how to use? If you outsource, ensure the firm you use reviews the project and helps you develop a budget prior to bidding the job.

As of now, I have no proven scientific formulas or calculations for you, nor real cost data. There really isn’t any. But I am researching BIM, as you should be. I’m just trying to get you to think about BIM and realize it’s more than a simple matter of throwing in a few thousand dollars for “coordination drawings.”

SHOOK is the president and chief estimator for his estimating company, TakeOff 16 Inc. He has worked in the electrical construction industry for more than 18 years. Reach him at 707.776.0800 and [email protected].

About The Author

Stan Shook was ELECTRICAL CONTRACTOR's estimating columnist from 2005 to 2012. He works as an electrical estimator in California. Read his blog at or contact him directly [email protected]


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