Bye Bye Blueprints, Hello BIM
If you stick to residential projects, you can hang onto your blueprints for now. However, if you see commercial and industrial projects in your future, you better be ready for building information modeling (BIM).
Ken Stowe, worldwide construction business development, Autodesk, San Rafael, CA, points out that BIM is very popular when constructing health care, university, commercial, and industrial facilities. “It’s not a technology as much as it is a way for the whole team to model a building,” he explains. “It helps the designers create a better design, it helps the contractors plan, fabricate, assemble, and install more efficiently and more safely, and it helps the operation and maintenance phase with efficiencies in energy and the cost of maintenance of the facility.”
Steve Hunt, BIM manager, Dee Cramer Heating, Cooling & Sheet Metal in Holly, MI, describes BIM this way: “Basically, it’s designing construction projects with 3-D software, so you’re actually building the project virtually and resolving conflicts in the model before the actual construction activities take place onsite,” he says. “Many potential conflicts during installation aren’t discovered on blueprints. These things are covered in the model environment virtually when nothing has been procured and nothing has been built.”
Identifying potential conflicts in the construction of the project early on saves time and money, Hunt says. “All the things that air conditioning contractors would install as part of their projects are being developed in a model environment,” Hunt says. “When you’ve had components put into a building information model and you’ve collaborated with the other folks, there’s a higher likelihood that what you intend to install will be installed as it’s designed without needing modifications in the field.”
Hunt thinks it’s foolish not to take advantage of building sheet metal in a controlled environment if you can. “We put as much of that duct together in the shop environment where all of the pieces, parts, and tools that you need are right there,” he says. “We can do that preassembly and ship it to the field in fewer pieces, which saves time and adjustments in the field.”
Stowe agrees. “One of the transformations that is going on is you nail down the geometry with confidence of the final product and now you can enjoy the saving from prefabrication and sometimes multi-trade preassembly.” Stowe indicates that BIM can also prevent unnecessary change orders. “Change orders delay a project, and delays can create the need for overtime and second shift s to get back on schedule. That’s costly. Plus, second shift s and overtime are an invitation to safety failure. Accidents happen when people are tired and they are rushing to ameliorate the effect of the delays.”
Another BIM benefit occurs long after the building is finished, according to Hunt. “The real benefit to the end user is BIM is really a life cycle to manage the facility by managing the costs of energy and maintenance,” he explains. “It becomes scheduled maintenance rather than dealing with emergency failures after things break. As long as that building is in use, the owner can extract benefits from the model by updating it as they make changes to the building or change out components or reutilize the space.”
Although BIM is primarily being used in commercial and industrial buildings, Hunt foresees a future for it in the residential market. “I’m sure eventually it will trickle down to just about anything being built, whether it’s residential, commercial, industrial, or whatever,” he predicts. “It will continue to grow in use.”
Ready or Not, BIM’s Here
Chris Gravelle, BIM coordinator and HVAC designer for Ventcon in Allen Park, MI, has been modeling in 3D since 1992. “As far as BIM goes, we draw ductwork and ventilation and build off our drawings,” he explains. “We were drawing in 3D before any of the other construction trades even thought about it. All of our pieces have embedded information to be able to build that piece right from the CAD into manufacturing. We send our drawings right into a fabrication shop.”
In the Detroit area, BIM is a requirement for the coordination of large jobs, he says. “We’re a ventilation contractor,” he says. “We do above-ceiling coordination. We get all the piping, ductwork, and electrical routed through the building and try to eliminate clashes. The biggest bulk of our work is the coordination. That’s a huge challenge right now because of finding people who are qualified. You have to know the trade. You can’t just be a computer guy. You have to understand how the work gets installed before you can draw it. Then you have to know how to run multiple types of software. We use Navisworks Manage for coordination, along with our CADmep soft ware.”
Over the years, Gravelle has fought his share of BIM battles. “Years ago, we would get fi les we couldn’t open up because they were drawn with another software,” he recalls. “That’s a problem with BIM. Everybody purchases software that is suitable for their needs, and they’re not all compatible with each other. We’ve learned to do the file conversions.”
He has also been involved in jobs where the architect won’t provide a model or turns over an incomplete one. “To have all the components of the building in 3-D requires everybody to participate,” he says. “That doesn’t always happen. As contractors, sometimes we end up drawing walls and ceilings in because we didn’t get a 3-D model from the architect. You can’t use an incomplete model for coordination. There have been jobs where we have drawn structural steel in, because they didn’t give us a model.”
In other cases, contractors have purchased inexpensive software that merely allows 3D drawing. Nothing more.
“Our stuff has always had embedded information,” he explains. “We’ve been able to run reports off what we draw to give us information on our parts and pieces. Anything we drew in 3-D, we could click on that piece and it would tell us the manufacturer, how it was made, how we were going to make it. To me, that’s information modeling. Some contractors don’t want to take the time or don’t have the software, so they will model stuff to represent pipes just using cylinders. That’s not information modeling. It has no intelligence. That’s the battle we have to overcome, because you can’t move ahead unless you get everybody on the same page.”
Ron Holdaway, senior design principal, Smith Seckman Reid Inc., in Nashville, TN, concurs, adding that many in the industry incorrectly use the terms BIM and 3-D interchangeably. “Building information modeling is a term that is being thrown around, but really all we’re doing right now is 3-D design and interference checking,” he says. “There’s nothing, at least from the mechanical, plumbing, electrical side, where we’re using the true nature of what BIM could really be.”
The conflict, he says, starts with model creation. “Everybody says that we should be able to create one model for the building. The architect should start that and then it should flow down to the engineers, and we engineers extract information about the architectural features of the building and plug it into all of our calculations. But it’s not working. There is a design model and there is a construction model in the industry, and right now the two do not communicate.”
Despite the current data exchange challenges, Holdaway has high hopes for the future of BIM. In fact, he is currently a corresponding committee member on an ASHRAE BIM committee charged with defining how data should be exchanged between models and engineering design software.
“It seems to me, for the next several years at least, we will be creating a design model, and the contractor will be creating a construction model, and there will be very little data swap between the two, but eventually it will happen,” Holdaway concludes.
BECOME AN ACCA MEMBER