BIM on the Job Site

BIM on the Job Site

Translating BIM technology and processes into lean construction practices

Adoption and usage rates of building information modeling (BIM) largely favor architectural, design, and pre-construction processes. Recent reports reveal architectural firms — with a 160% increase in the adoption rate between 2005 and 2009 — as the prime driver of the technology. Accordingly, architects, structural engineers, and construction managers/general contractors are most often perceived by their project team members as receiving the most value from BIM, according to results of a survey published in New York-based McGraw-Hill Construction’s report, “The Business Value of BIM: Getting Business Information Modeling to the Bottom Line.”

By comparison, the perceived value of BIM for specialty contractors ranks second lowest. “Although specialty contractors are charged with executing the complexities of a project, few team members (23%) believe they are experiencing high value from BIM,” reads the 2009 report (click here to see Fig. 1).

Yet, according to additional survey results included in the report, three in five mechanical, electrical, and plumbing (MEP) contractors say they have adopted BIM — a trend that matches the reported adoption rate of architects. “Shifting detailed design and modeling to trade contractors is an increasing trend on BIM projects,” says the report. “This may be one of the reasons the data shows MEP engineers trailing all other design professionals, while MEP contractors boast a significantly higher percentage of expert and advanced users than construction management, general contracting, and other contractor types.”

It’s complicated

Results of another 2009 survey funded by the National Electrical Contractors Association (NECA), Bethesda, Md., indicate 20% of electrical contractors — 36 out of 184 responding companies — are using BIM technology. Of that group, 92% had used BIM technology in 10 or fewer projects. (For information on the electrical industry’s difficulties with BIM, read “Growing Pains” in the March 2010 issue of EC&M.)

Types of projects the electrical contractors were using BIM on include health care and commercial buildings, followed by industrial, education, government, and manufacturing facilities. Often, the level of complexity of the project determines the involvement of the field supervisors with BIM.

“On the more complex projects — laboratories, hospitals — we tend to have the foreman or field supervisors involved very early in the process so that they can assist in controlling their destiny,” says David Morris, director of virtual construction for EMCOR Group, Inc., a Norwalk, Conn.-based electrical construction, energy infrastructure, LEED construction, design/build, life safety, and facilities services firm.

Since 2005, EMCOR has provided BIM services on more than 500 MEP construction projects valued at more than $100 billion. “But there has to be something down for them to look at, and it has to be relatively stationary at the point they look at it,” Morris continues. Therefore, EMCOR involves the electrical contractor early in the coordination process, but not typically in the design or pre-coordination phase.

BIM includes use of software to create a 3D model, which is linked to an information database. So far, the primary function of the model and database has been to aid in the design of a building. However, as the technology matures, it’s being used to construct and also operate/maintain the facility through visualization of the building systems. Recently, programs have begun allowing for the collection of building performance metrics, such as energy use.

Results of the NECA study reveal that, of the electrical contractors who use BIM, most use is in the pre-construction and construction phases (click here to see Fig. 2). However, more than 50% of the respondents use BIM technology in either of the phases, whereas only 30% of respondents use BIM in every phase of the project life cycle.

Four in five specialty contractors that use BIM report positive returns on investment (ROI) in the technology, according to the McGraw-Hill 2009 report. Of those using BIM, 44% are creating and analyzing models, but other capabilities the MEP contractors value include spatial coordination, pre-fabrication, and quantity takeoff. The NECA survey results include spatial interferences, visualization of electrical design, space use, trade coordination, and shop drawings submittal and review (click here to see Fig. 3).

For the first time, the construction team can visualize when and where other trades will work and schedule the sequence of events accordingly. Laydown areas and deliveries can also be marked off and scheduled. Pre-fabrication comes next. “If you’re not pre-fabricating after you’re spatially coordinating, you are not reaping the benefit of the investment you put into the process,” Morris says.

Space patrol

During the construction phase, Katie Jones, CADD designer for the electrical division of Total Facility Solutions (TFS), Inc., Plano, Texas, which provides electrical contracting services for its clients, coordinates with all the other contractors on the site to make sure everything fits accordingly. “I come in when they are physically ready to start coordinating,” says Jones. “When I come onboard, everybody’s starting to test the waters to see where it all fits. We use the BIM model for that main purpose.”

From switchgear rooms to panels and transformers, she uses the construction drawings to make sure it fits and still meets all the criteria of what’s required electrically. Typically, the only changes Jones makes to the model are for routing to accommodate ductwork or piping. ”I don’t change anything when it comes to sizing,” she says. “I just find better ways to route it from one end to the other. Everybody shifts a little bit here and there to accommodate everybody else.”

The coordination is part of the construction phase, although, obviously, it must occur before the electrical systems are physically installed. “It’s pretty back-to-back,” Jones says. “As soon as something’s ready, it gets installed.” Locating equipment is the initial step. The large equipment goes in first, which is often why the electrical systems, comprised of smaller parts, are not modeled as often as structural or mechanical components.

Although field labor is not involved in any of the coordination process, Jones works closely with the project manager and sometimes the foremen and superintendent. “They still use typical construction drawings,” says Jones, who supplies them with a print to show locations of the equipment and elevation, if there are any. “That way, I don’t hand them a drawing only for them to hand it back and say, ‘This won’t work, redo it.’ I’d rather get it right the first time when I hand it off.”

The tail end

In July 2009, after a 13-project pilot program, Wisconsin became the first state to require the use of advanced BIM technology for all state projects with budgets totaling more than $5 million and new construction projects more than $2.5 million. Under the state requirement, several members of a project team — architects and structural, mechanical, and plumbing engineers — must provide BIM models or work on the same model. The requirement does not cover the work done by electrical professionals. Nonetheless, Madison, Wis.-based electrical contractor Westphal & Co., Inc., uses BIM on approximately 50% of its projects, particularly when providing design/build and design/assist services. “We don’t use BIM on a project unless everybody’s using BIM,” says Kevin Bollendorf, director of engineering services. “The tail can’t wag the dog.”

Generally, the electrical contractor receives direction from the electrical engineer, who is dictated to by the architect. “So the architect will make changes to the model, trying to improve the quality of the work. But in the meantime, the general contractor has probably already started on the project so some of the changes are made after the project starts, which causes difficulty because all the electrical engineer can do at that point is react instead of being proactive,” explains Bollendorf. “They almost have to be reactive, and then so do we.”

The compressed schedule can cause a delay in information relay, according to Bollendorf. “Ideally, you would construct the model in the virtual world, and once that’s ready to go, you would start construction,” he explains. “But the timeframe is still crunched, so trying to get information from engineers who are trying to get information from architects is still a little bit of a struggle.”

In a perfect world, says Bollendorf, everything would be lined up before the construction phase. “The reality is we’re not at that point yet,” he continues. “It’s going to be a few more years and a few more projects for people to really fully comprehend how crucial some of that information is. All in all, though, it works pretty well.”

To ensure accuracy in the field, the company has invested in BIM and CAD training for job-site field staff. “We have electricians on staff working with us on the actual layouts,” says Bollendorf. “They know what they can actually bend in the field as well as how things should be put together — and that streamlines our installation process quite a bit. Everything gets installed just how it is in the model.”

According to the company, this also assures fully accurate as-built BIM models and drawings at project completion. In addition, the up-front investment in electricians with CAD and BIM experience cuts down on laborers at the job site. “Because we’re laying out work, we can stay ahead of it,” Bollendorf says. “We don’t have to have quite as many people on job sites, and we can avoid a lot of those fire drills on the BIM projects.”

The paper trail

Under BIM, deliverables include more information than with traditional project delivery methods. “By and large, the actual documents are much more complete,” says Morris, who explains that in the past there were just schematic documents and everything was field routed. Now, through the use of BIM, there are installation shop drawings that have elevations and dimension centerlines.

“The actual documents are much more complete,” says Morris, who explains that in the past there were just schematic documents and everything was field routed. Now, using BIM tools, installation shop drawings have elevations, dimensions and centerlines. Although they are typically a paper deliverable, they are complete in sections, details, and elevations. “The electrical industry has always been light on deliverable documents from designers to contractors and contractors back to designers,” Morris explains. “BIM has raised the bar substantially. This is a level of deliverable that historically hasn’t been available for the electrical side of things.”

In some cases, particularly on more complex projects, electronic models are made available through computers on the job site. “We encourage the use of those graphical information models, but it depends on the complexity of the project,” Morris says. “On a simple job, paper documents still function well.”

The deciding factor, says Morris, is that the currently available hardware for field use won’t stand up to the field environment. “The technology isn’t reasonably ruggedized enough to haul around in a construction setting,” he says. “Most hardware isn’t robust enough for use on a construction site, and if it is, it’s very expensive. There are promising solutions, and we definitely have our eye on them. As the technology evolves and prices come down, adoption will increase.”

Also slated for the future is the use of applications, or apps, such as Google Earth, in conjunction with the BIM software. “We’re working on being able to export the 3D model into a type of file that Google Earth will read,” says Tony Locknane, engineering technician II for Dairyland Power Cooperative, La Crosse, Wis., a generation and transmission (G&T) cooperative that provides wholesale electrical requirements and other services for 25 electric distribution cooperatives and 16 municipal utilities in the Upper Midwest. “We’re exploring if the construction crews can use the actual Google Earth function with our poles and lines in a 3D world. We’re looking at that, but we’re not quite there yet.”

However, other firms currently use laptops in the field. “We’ll print the project managers a 3D rendering of the actual area, and then the field foremen will use laptops to view exactly what they’re installing,” says Bollendorf. “That picture is generally worth a thousand words.”
TAGS: Design
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