Building information modeling (BIM) moves building design out of the two-dimensional realm of computer-aided design (CAD) and greatly increases the construction team’s ability to control and manipulate data and information. The technology is particularly useful in design/build projects because it combines all of the building objects to create an intelligent design that coexists in a single database. It creates a virtual building that provides, in theory, a single, logical, consistent source for all information associated with it.
The immediate benefit of BIM is its three-dimensional (3-D) capabilities. BIM provides object-based parametric modeling—taking an object, along with all of the data describing its components, and placing it in a computer model that is a virtual, digital description, rather than a simple geometric description of the object. It facilitates collaboration, allowing more project stakeholders to have an active role in understanding the building and optimizing the entire design and construction process.
However, BIM actually goes beyond 3-D and allows the construction team and design/build electrical contractor to use the database to manipulate and control time and costs (the fourth and fifth dimensions of projects).
Whether new construction or renovation, no work occurs in a vacuum. It all must be sequenced, said Bob Middlebrooks, industry program manager for Autodesk Inc., San Rafael, Calif.
“BIM has the capability to capture time by flagging different parts of the building as belonging to different phases of the project and communicate conditions and sequences over time to the entire construction team,” he said.
Of course, sequencing the work is most important during the construction phase, and BIM allows the contractor to be more sophisticated in coordinating activities with the owner and the rest of the team. BIM graphically determines the project’s time schedule, can ensure that it remains on track and can be used to instantly analyze what the result will be to the schedule from any changes in construction activities. It also is helpful in renovation projects, where existing facilities remain operational, by allowing the contractor to visually understand how to sequence work to avoid disruption.
Along with the opportunity to better understand construction sequences, BIM’s fourth-dimensional (4-D) simulations offer contractors the ability to examine cost-effective or efficient alternatives more closely, according to Brad Workman, vice president of global building and plant solutions for Bentley Systems Inc., Exton, Pa.
“But the biggest need for the sequencing capabilities of BIM is in space-constrained construction sites, where staging for materials is critical,” he said. Four-dimensional modeling enables contractors to stage and store materials in the proper sequence, avoiding scheduling delays or conflicts.
In the design phase of a project, BIM’s 4-D abilities allow the contractor to coordinate time issues early, rather than in the field.
“The idea is that conflicts are cheaper and easier to resolve if they are discovered before work begins,” said Bob Robison, vice president of business operations for Design Master Software Inc., Shoreline, Wash.
The fifth-dimensional (5-D) aspect of BIM is cost. Every object in a BIM model is discrete and is intended to represent a real object to be installed. By assigning costs to each of those objects, a complete cost estimate can be built. According to Workman, designers can get a deeper understanding of component costs through BIM’s 5-D capabilities.
“The model demonstrates total project costs resulting from changes made to particular components or objects, enabling the designer and construction team to make more cost-effective choices and better respond to the consequences of various costs,” he said. And since the model provides accurate information about the number of components and the types and amounts of materials required, relative cost estimates can be easily changed.
BIM advantages in design/build
In the construction industry’s quest to improve efficiencies and streamline construction processes, BIM lends itself particularly well to design/build projects. BIM merges the design and construction processes, providing better control over design efficiencies. It allows the electrical contractor to design layouts, networks and systems that are more efficient and based on real-world experiences.
“The biggest value of BIM in design/build situations is its ability to confirm the design intent early in the process, enabling the contractor to make decisions to optimize it,” Middlebrooks said. Those decisions can be communicated to the entire team early on, reducing risk and improving construction predictability.
For the contractor, BIM allows the data in the model to flow from one process to another, eliminating duplicate entries into different computer systems.
“Design/build projects particularly benefit from that flow of data, allowing the contractor to save time in both the design and construction phases of the project,” Workman said. And since BIM encourages better collaboration and earlier integration of the electrical contractor into the design process, construction is streamlined. “BIM allows early consideration of constructability issues and enables alternatives to be studied and decisions to be made before work begins in the field,” Workman said.
Since BIM’s goal is to optimize the project for everybody, the electrical contractor can use it to design the electrical system to adhere to the best construction processes.
“For example, BIM provides the contractor with the opportunity to influence the location of the primary electrical gear and to optimize its installation. It also allows the contractor to bring its expertise to individual components and systems, such as energy modeling,” said Forrest Lott, AIA, LEED AP, principal of Lott + Barber Architects, Savannah, Ga.
According to Mark Shambaugh, CEO of the design/build electrical contractor Shambaugh & Son L.P., headquartered in Ft. Wayne, Ind., the most recognized advantages of BIM include early conflict identification and mitigation, early visualization and optimization of space planning, fewer errors in the field and higher reliability of expected field conditions, increased prefabrication opportunities, and improved installation productivity.
“Field forces can hit the ground running much faster when the job has already been modeled and prefabrication is optimized, reducing both cost and time needed to complete the job,” Shambaugh said.
But what if the electrical contractor doesn’t have BIM capabilities yet? Can the company still participate in such a project?
“Assuming BIM is involved in the project, the contractor can still acquire models from the architect and other trades and aggregate them to get an understanding of the physical layout of the building,” Middlebrooks said.
But, he cautioned, the contractor should not assume that it can go into the field without ensuring its construction activities adhere with the model and its determined sequence of events. And, of course, even without BIM, the electrical contractor can still help review the design of the electrical systems and ensure constructability as well as influence the model. Another option, according to Robison, for an electrical contractor without modeling capabilities to participate in a BIM-based design/build project, is to partner with a local engineering firm that does.
Making the investment
How much time, money and effort it will take to invest in BIM depends on the skill levels of the individuals in the company, but according to Middlebrooks, it usually includes the acquisition of software, personnel training and some additional hardware and infrastructure. Software costs can range from $4,000 to $8,000, and training costs can range from $1,000 to $2,000 per day, depending on the number of people being trained.
“Every firm is different, so the investment levels depend on existing design and computer expertise and the willingness of project teams to adopt the technology and the new processes that will be required,” Workman said.
Because BIM is transformative and will change the firm that begins to use it, according to Lott, it is not for occasional use.
“The investment in people and training requires commitment and a long-term goal of using BIM as the company’s primary design and construction tool,” he said.
To introduce the technology into the company, Middlebrooks advised, pick one project that is manageable in terms of time and profitability.
“Under no circumstances should the contractor expect to be up and running with BIM immediately,” he said. Involve the best people in the company early, and let them determine work flow on smaller projects. Then slowly diversify and gain knowledge at a steady pace. “Once the company has mastered the new processes that go along with the use of BIM, the company can move up to larger projects and hopefully realize larger gains in time and money,” Robison said.
Shambaugh advises having either peer group members or outside consultants effectively train people from the onset.
As the industry becomes more comfortable using BIM, it will expand to be used to more fully analyze projects and determine sustainable design, building performance and energy usage.
“Consulting engineers, subcontractors and suppliers are now beginning to participate in BIM, and as more people use the information BIM offers in more ways to virtually determine building and component parameters earlier in the design process, project outcomes will continue to improve,” Lott said.
BREMER, a freelance writer based in Solomons, Md., contributes frequently to ELECTRICAL CONTRACTOR. She can be reached at 410.394.6966 or firstname.lastname@example.org.