Industry experts say modular building technologies—which allow for the prefabrication of modules in a warehouse or manufacturing facility for seamless on-site installation—can offer tremendous advantages over traditional stick-built means. This derivative of the design/build method produces key project components off-site and is sharpening the competitive edge for some electrical contractors (ECs) in a recovering economy.
Major activity in mass prefabrication for system building dates back to the construction of houses, churches and hospitals in the early part of the 20th century. The modular concept has been credited with mitigating job site delays, increasing worker safety, decreasing production waste and providing greater assurances of quality, delivery and cost. Some of the primary drivers behind prefabrication in a controlled environment include aggressive production schedules, repetitive floor plans, congested work sites and weather constraints.
“We can have people working on a project in an off-site location, assembling modular units that can be installed at a later date. That schedule flexibility, along with providing an edge on some of the competition, is also driving it,” said Mark Smith, senior project manager at Dayton, Ohio-based Chapel Electric Co. LLC.
Examples of modular building are everywhere. For instance, retail giants, such as Target and Walmart, employ commercial applications of modularity to construct flexible and cost-effective retail space. And, according to Bill Mazzetti, senior vice president and chief engineer at San Jose, Calif-based Rosendin Electric Inc., the construction concept is currently having a revolutionary impact on the delivery of data center facilities.
Providing the ability to deploy additional mission-critical capacity with greater labor efficiencies is significantly condensing construction timetables and transforming the way hospitals, schools, offices, high-rise residential buildings, hotels and geothermal plants are being built.
“The reason we got into the modular business was to simply raise our competitiveness. We feel it is an irrefutable and irreversible trend in the industry,” Mazzetti said, pointing out that the company’s interest is accelerated by information technology manufacturers and general contracting firms who are seizing the scope and control of electrical fabrication work. He believes this practice can and should be pursued by a skilled EC work force.
“If we don’t do the work, we know somebody else will. Frankly, I see a great deal of use for modularity in many areas and in all disciplines,” Mazzetti said.
Susan Hines, managing director of public relations and information at the Design-Build Institute of America, said electrical prefabrication is creating a new dimension for design/build methodologies.
“Design/build is all about bringing as many people to the table as early as possible in the process to harness creativity and knowledge, and that includes fabrication,” Hines said.
She acknowledged modularity doesn’t stop with prefabricated steel and concrete.
“Electrical prefabrication is another tool in the toolbox to do a job on time and on budget to meet a customer’s needs,” Hines said.
“Mechanical plant, piping and ductwork fabrication is a mature and well-adopted construction technique,” Mazzetti said. “In many ways, electrical has been the last person to the party.”
According to Thomas Korman, associate professor of construction management at Cal Poly State University, San Luis Obispo, Calif., constructability is further enhanced when ECs can proactively access design intent and apply intelligent 3-D modeling technologies to the integrated project delivery method.
“With native electronic files, they’re able to tailor their design to be installed and fabricated easier. It results in a higher profit margin because they’re not stuck with a design that’s not buildable,” Korman said.
Korman said that with the increased use of building information modeling (BIM), electrical modularity becomes more effective and valued because the entire developmental process from planning and design to drawings and manufacturing can be streamlined with measurable results. Prefabrication accuracy and efficiency can be further enhanced when based on information modeling that helps identify and resolve conflicts between structural and mechanical, electrical and plumbing (MEP) designs.
As integrated project delivery methods evolve, Korman expects to see more reliance on MEP plans that incorporate virtual building for optimum prefabrication.
“It’s hard to do modular construction without information modeling,” Korman said, adding that the coordination can be worked out in the model, and repeated electrical components for multiple rooms or locations can be copied and pasted.
“ECs can do much larger sweeps, conduits and bendings to the proper radius in their shops. They can go to the level of pulling wire into wall and ceiling sections before delivery rather than pulling it all in the field,” Korman said.
A common misconception in the industry is that prefabrication can only be effective in repetitive designs and larger projects. Not so, said Joan Fultz, Chapel Electric Co.’s prefabrication manager.
“The planning and design upfront may be more intensive, but components on any floor can be prefabbed,” she said.
It can be as simple as packaging lighting fixtures in a controlled environment and cutting and bending conduit to specific lengths. Chapel Electric Co. routinely assembles panel enclosures and transformers in its shop and has preproduced metal-clad cable assemblies for stud walls and voice/data/video raceway drops for site installation.
Data center directive
“While originally seen as a platform-specific application, mechanical and electrical systems are now being elegantly and efficiently packaged, completing the modular circle,” writes Mazzetti in a blog post, “The Biggest Data Center Trends for 2011.” In practice, Microsoft, HP, IBM and Dell have adopted the concept with construction of scalable, energy-efficient units to house cloud-computing platforms and other online capacity issues.
And ECs are getting involved. For instance, Rosendin Electric Inc. completed its first mission-critical project in 2010 and put an agreement and resources in place to provide a factory setting for prefabricating an electrical room for a data center.
Mazzetti reported that after the firm accepted the 24-week job, the schedule was compressed into 14 weeks. In partnership with Rosendin Electric’s wholly owned subsidiary, KST Electric Ltd., and ACS, both located in Texas, the structural steel work, raised floor systems, enclosures and wiring were all completed in the factory on time and transported by truck to California. The four large sections were dropped into the building for final connections in less than 18 hours. In a more containerized solution, Rosendin Electric can subcontract additional mechanical functions, such as heating, ventilating, air conditioning and fire alarm systems.
Fundamentally, Mazzetti said, the modular approach transfers labor from the field to the factory with cost advantages that extend to the union labor model.
“You can work issues simultaneously. We don’t have problems with labor stacking on the job site when you may not control the material flow or the equipment delivery, and we know what it’s going to look like before we deliver it,” Mazzetti said.
Overall, when comparing modular construction to stick-built construction for data center construction, Mazzetti is confident modularity is a better method all around.
“We’re getting better quality, getting our product there quicker, and it’s a lower total cost of installation than we would normally pay,” he said. “If I have equipment in hand, we can turn an electrical system in three to five weeks from order placement. It’s insanely fast, and the quality goes up.”
Multiple trades and markets
Chapel Electric dipped its toe into the modular stream in 2001. Fultz joined in 2003 to establish a prefabrication program and serve as a liaison between its prefabrication foreman and the project managers. The program has completed a couple of large projects every year, including a nine-story apartment building, offices on an Air Force base, multiple schools, industrial conveyors, and additions to the National Archives. Less than a decade after the program’s development, the company secured the opportunity to participate on the nation’s first multitrade healthcare prefabrication team.
The 484,000-square-foot Miami Valley Hospital in Dayton, headed up by Skanska USA Building Inc., is believed to be the most impressive prefabrication project in the country. According to Smith, the electrical portion of the 12-story project was performed as a design/assist process with Skanska, in conjunction with the project engineers.
“Design/assist helps us work with the owner better to provide the systems and products that they want in their building. At the same time, it enhances the overall project schedule,” Smith said.
Collaborative MEP prefabrication of 178 patient rooms and 120 overhead-corridor racks trimmed more than two months from the construction schedule, cutting 1 to 2 percent off the cost of the $152 million facility. Chapel Electric Co. crews performed the prefab work in a warehouse two miles from the project. There they built the corridor rack modules, bathroom pods and patient room headwalls and footwalls. Between 35 to 40 percent of the project was built off-site.
Marty Corrado, project executive for field operations in Skanska’s Nashville office, said that electrical prefabrication was vital to construction on a tightly configured site with no staging area.
“What makes this process so unique is we used our subcontractor trades and did all the work off-site that would’ve normally been done on-site. To be able to put all the conduit and all the cable trays together off-site, it cut down the waste and was that much less material to be delivered and distributed around each floor and installed one piece at a time,” Corrado said.
The multitrade prefab offered all the benefits of a single-trade approach: a controlled environment, increased labor efficiencies and leaner production using a total of 18 workers. Despite the high volume of prefabrication, safety improved significantly over a traditional commercial work site. No shop injuries or accidents occurred.
“No one worried about climbing ladders or falling into rough terrain,” Smith said.
Smith and Mazzetti continue to push the modular concept forward, having seen few limitations.
“I actually think the owner receives a better product from a quality perspective because materials are installed in a controlled environment, and the building is usually up and covered before installation,” Smith said.
“I think the only issue becomes if you really don’t have a clear idea for manufacturing or a jurisdiction that doesn’t understand it, then you’re going to get garbage in and garbage out,” Mazzetti said.
Though he sees modular construction as a trend in this marketplace, it hasn’t settled itself out yet.
“But it’s here, and it’s here to stay,” Mazzetti said.
MCCLUNG, owner of Woodland Communications, is a construction writer from Iowa. She can be reached at email@example.com.