The philosophy behind Building Information Modeling (BIM) is more than the sum of its technological capabilities. Proponents of BIM claim that — beyond the technology's integrated database — it fosters a collaborative effort, enabling the soup-to-nuts cooperation among owners, architects, engineers, contractors, trade professionals, and building operations/facilities personnel. “BIM is really bigger than any one user,” says Robert Weygant, the BIM practice group chair/convener for the Construction Specifications Institute (CSI), Alexandria, Va., and owner of Sumex Design, Nottingham, N.H. “It's a single location where design considerations, installation instructions, maintenance information, handling guidelines, and life cycle and warranty information are available. This could potentially turn a BIM model into a digital owner's manual.”
Yet, many electrical firms using BIM software subvert the generally accepted terms of collaboration surrounding BIM. Jewell Electric, DuBois, Pa., creates 2D blueprints for design-build projects with the BIM software, bypassing any delays that may be caused by requesting them from an architectural or engineering firm. “On one job a few years ago, I went through the other channels, calling an architect or engineer, and it took four or five weeks longer to get the plans than what they told us,” says Don Jewell, president of Jewell Electric. “My customer was getting irate, so I started searching around for a program to help me. Granted, I can't stamp them because I'm not an engineer, but I can pass on the information to the general contractor.”
Because mechanical, electrical, and plumbing (MEP) firms already use computational tools for analysis, they may underestimate the benefits of BIM. However, the recent integration of analysis in the BIM model may signal the tipping point in favor of adoption. This development — coupled with the value the integrated model provides in enabling systems clash detection and coordination — are providing the impetus. “As far as printing out the light fixture schedules and the switchgear packages with breakers, it does a great job,” Jewell says. “Overall, it can give you an extremely close material list for a job.”
In fact, some electrical firms use BIM software without realizing it. “None of our customers would say they use BIM, but they really are; just not in the sense of how BIM is defined or how anyone actually talks about it,” says David Robison, software developer for Design Master, Shoreline, Wash.
Data mining
At its most basic, BIM technology is an object-oriented database from which model drawings (in both 2D and 3D) can be extrapolated. The BIM database can contain detailed information at both the component and overall building level, such as building geometry, spatial relationships, geographic information, and the quantities and properties of building components. As architecture, engineering, and construction (AEC) project team members add information to the database, the building model is modified automatically to reflect the updates. “Data is the heart of BIM,” says Weygant. “Without it, BIM is little more than 3D CAD with a few bells and whistles.”
Unfortunately, existing MEP programs for BIM — plagued by a steep learning curve, complicated operability, and a lack of technical support/training — are still in the early stages of development. They also represent a significant up-front investment in hardware to run the BIM application (see System Requirements.) “The mechanical industry has been using BIM for a number of years,” says Marlon Pullins, virtual electrical designer, Pullins & Associates, Chicago. “That's why a lot of the BIM packages cater to the architect and the mechanical trade. Electrical is a good three or four years behind.”
In comparison to architectural BIM, MEP for BIM comprises more technical and industrial components and connections. Also behind the delay in BIM adoption by MEP design firms has been the lack of data from MEP manufacturers in a form readily usable by BIM applications. “Right now, all the information that goes into a BIM model is not formatted in a way that everybody can easily use it,” says Weygant. “The development of something like a Dewey Decimal System for BIM is desperately needed.”
Currently, MEP extensions for BIM programs offer information for generic components. For instance, for a switch an end-user can insert voltage, amperage, and real power values. Any additional information is the responsibility of the end-user. To bridge the gap, many firms create their own database of manufacturer information. “I have my own electrical tool palette that's customized to keep me flowing faster than with everyone else,” Pullins says. “It covers everything electrical — from pipe to switchgear.”
A customized tool palette represents a significant investment in time and staff power. This can slow the return on investment (ROI), even when outsourced. To complete his, Pullins spent a couple of years working within the program. “Right now, the programs out are not yet electrical savvy out-of-the-box,” Pullins says. “Someone has to work the program to get it to do what you want it to do, take notes, save the notes, and then create something to work for someone to learn how to use it.”
Another issue regarding content creation is that BIM platforms can accept an infinite amount of data. Therefore, the firm must determine the complexity needed for the model. “If you have 500 parameters inside a family, you'll have a hard time finding them when you need to actually use them,” Weygant says. “There are ways around this, like hidden shared parameters, but then you don't even know the data is there, unless you schedule it out or run a database dump.”
End-users can also decide between linking the information inside the actual model or linking it to an outside source, such as a pdf or HTML page. However, as more manufacturers begin releasing their data in BIM format, content creation for electrical firms will become easier. For instance, information for lighting fixtures will be linked to each fixture and given an attribute that can be viewed by clicking on it. “Is this light fixture rated for 208V or 240V?” asks Weygant. “Is this a low-voltage device? What is it used for? How does it interrelate with other devices? You have to make sure that all of them work correctly inside the software and have the information that speaks to a specific device — not just a generic version of it. That's a very high-level view of product information that's bigger than one singular BIM user.”
Potentially, manufacturers could rely on third-party companies to provide the information to the BIM software. These companies could use the same model as Arcat, the library for the architectural community, which contains about 450 BIM models with performance, life cycle, and usage data associated with the product. “Where I see the level of content coming from is third-party agencies that are developing content for the manufacturers,” Weygant says.
Trade Service, San Diego, hopes to leverage its content within BIM applications. “We're already exploring BIM and are forming some alliances with people that support BIM applications,” says John Henry, director of business development, Trade Service. “It's on our radar as something we're moving ahead with.”
Henry agrees that, right now, the graphics side of computer-aided design — the physical product — is extremely high-profile. Generally, what's missing is the actual content that lies beneath,” he says. “They don't have very many links, yet, to a database like ours, for example, to pull in the materials pricing and the extensive content associated with the actual materials that end up being purchased and installed in the finished building,” Henry continues. “BIM is the buzzword people are using, but so far it doesn't tell the whole story. Ultimately, while focused currently more on CAD, BIM will need to embrace the underlying product, pricing, and labor content before it reaches its full potential as the ultimate building design solution.”
Trust fund
At worst, the traditional relationship between engineering and contracting firms can be described as “antagonistic;” at best, “mutually suspicious.” Overcoming years of bad blood caused by lawsuits over liability may take more than an impressive software application, according to Robison. “If you talk to an engineering or contracting firm, they're not going to want to play nice,” he explains. “Everything about their interaction is about reducing liability.”
Therefore, the engineering firm may not want to supply further ammunition to the contractor in the form of take-off data, for example. “If there's a problem with it, it exposes the firm to liability,” Robison says. “By releasing this information, there's no gain and a huge chunk of liability. They don't want to share the information, so they force the contractors to recount, even though they already have those counts.”
One of the main reasons behind the adversarial relationship is confusion over component data. A standard BIM tool palette could help alleviate issues of liability and foster an information-based collaborative process. “Trust — that's what it boils down to,” Pullins says. “Everyone has to share files, but typically the architect is going to be the main person distributing the central file for us to work off of. We can monitor the architect's changes, so if he makes changes to the floor plan — and if it affects our electrical equipment or room — we get a notice. That puts us on the phone with the architect, and we'll need to coordinate it.”
The sharing of information can also enable data reuse throughout the life cycle of a project. An investment in BIM software could actually add value to the model, including space planning, quantities, facility maintenance records, furnishings, and inventory, as well as recording changes throughout the facility life cycle. “You're able to provide a digital owner's manual of the building on completion, so facilities managers can take that building (and all of the information contained within it) and use it for the life cycle of that building to help budget for a new roof 25 years from now, to budget for new cladding, and note how often you need to change bulbs and at what point,” Weygant says. “You can run reports inside of that model or extract information from that model to run reports.”
However, the free flow of information is also a cause for concern. “Once the project is fully done, you've shared everything,” Pullins explains. “Another electrical entity could get a copy of our drawing, take the blocks out that we've spent time designing, and use it for a job that they're going to do at some point down the line. But I'm sure that security issue will be handled some years down the line as it gets more involved.”
Model behavior
Electrical firms that adopt BIM use it in various ways, such as visual scheduling and quantity take-offs. Digital fabrication workflow is also made possible through the software. Using BIM, firms can much more easily fabricate their building systems directly from the BIM model, especially when the system or building design within the model is created specifically for fabrication. The model can then be used to fabricate premanufactured components such as ductwork and cabling that can be delivered in racked systems or modules. “There's such a benefit to using BIM software in the electrical industry,” says Weygant. “Being able to take a model of a building created by an architect and insert every single fixture and wire — and from there extract a quantity take-off — is a distinct advantage. They can simplify the estimation process and be able to double check open circuits and really get themselves involved with the process earlier. It also give them a competitive advantage by being able to read and understand a BIM model above and beyond a set of paper drawings that they get in their project.”
However, modeling itself is actually a low priority for most electrical firms that have adopted BIM. “I don't even know if I've even seen a drawing in the 3D,” Jewell confesses.
Results from a survey of BIM users published in the SmartMarket report, “Building Information Modeling: Transforming Design and Construction to Achieve Greater Industry Productivity,” conducted by New York-based McGraw-Hill Construction in conjunction with 2D and 3D design and engineering software developer Autodesk, San Rafael, Calif., reveal that on a scale between one and 10 for frequency of modeling with BIM, the mean for electrical system rates only 4.38, well below the mean for architecture at 7.06, structural at 6.33, and mechanical at 5.41 (click here to see Fig. 1). To read the report, visit the CSI Web site at http://www.csinet.org/s_csi/docs/16600/16526.pdf.
The lag may be largely due to a lack of interest seeing electrical components in the renderings. “First and foremost, you have to look at the graphical aspect of it,” Weygant says. “How relevant is the actual appearance of the receptacle to the big picture of the BIM? Nobody really cares what the receptacle looks like as long as they know it's a 15A and 120V. It's the information about those components that really drives the BIM.”
According to the SmartMarket report, electrical coordination issues are less challenging so modeling is less critical. “We have 3D modeling capability, but it's not something we push hard electrically,” Robison says. “They can do it, but they ask why they would want to do it.”
Although BIM is known as an enabler of green technology and energy efficiency, electrical engineers and contractors rarely model energy management systems. A quarter of electrical engineers and contractors that use BIM model light fixtures more than any other element (click here to see Fig. 2). “When it gets to the level of saying I want to know what each of those devices looks like, in the case of decorative fixtures, then the onus goes back to the manufacturer to provide that to them, with all its related information, so it can be viewed properly,” Weygant continues. “So it will be, ‘This is what my device will look like when installed in the wall or floor or ceiling, and this is how it will perform once it's implemented into the entire system.’”
In addition, electrical elements tend to be smaller in size than structural or mechanical elements. “They're overshadowed by mechanical and structural elements,” says Weygant.
Choosing electrical components, however, can depend on the project's niche market, says Pullins. “With a data center, there's a lot of electrical work and big pieces of equipment that are running off of generators,” he says. “So with a data center, BIM can be used fully. But on most electrical projects, it looks good but is the cost there?”
According to Pullins, it's hard to know how long it will take to model a floor in 3D. “Most electrical companies try to avoid the 3D because they can't build the cost in for 3D,” he explains. “The architects can sell it to the customer, and the customer will buy it. But when it comes to electrical — and they're charging $100 an hour for engineering, plus you've got a floor that's going to take 20 hours and another that will take 15 hours — there's no way to determine how each floor is going to go until you actually start drawing it. I think that's a reason a lot of these guys avoid it.”
Sidebar: System Requirements
A collaborative BIM process requires all trades to have live interaction with one another. This requires large amounts of computer memory and processing power. “If the whole job is not on the program, with everyone using the same program to do the 3D, then it's really not effective,” says Marlon Pullins, virtual electrical designer, Pullins & Associates, Chicago.
At around $5,000 per station license, the up-front investment costs in BIM software can be expensive. And the larger the firm, the greater the initial cost. “It's costly software to run,” says Pullins.
Related costs include hardware, software, network infrastructure, and training, as well as development of a customized tool palette. The minimum computer system requirements to run 3D CAD programs typically consist of a Pentium 4 processor (1.4 GHZ or higher), 1 GB of RAM, and a 1024 × 768 VGA display screen. Some firms may even need dual processors or a dedicated computer for running 3D CAD iterations. Although the majority of work on BIM will remain digital, the process will still require a high-quality, large-format, color technical document system to produce hard copy output of BIM-generated designs.
The change in process, which moves the bulk of work to the initial project phases, can also incur cost and time delay. In some instances, companies have taken three or four years to realize a return on investment (ROI) on BIM. “It's software you have to customize,” Pullins says. “Some firms don't want to spend extra money to teach the CAD person what it is. They think it's strictly 3D, but it's not. There's a lot of intelligent data inside that 3D drawing that makes it a building information modeling drawing. The information is built into that project. You can actually click on it. It's built in with the intelligence.”
