NO MATTER THE TYPE OF PROJECT, AUGMENTED REALITY CAN HELP
BY DEBRA WOOD
Contractors use augmented reality (AR) in a number of ways on a variety of projects to show clients a space, resolve clashes and under-stand how much work has been finished.
“McCarthy deploys AR when a client or project has a need to review existing conditions in a building or on a construction site against future installed work,” says Chris Patton, regional manager of Virtual Design and Construction for McCarthy Building Cos.’ Southern Region, a member of multiple AGC chapters. “This can range from the aesthetics and orientation of an entire building on a site, to the routing of a single routing above a ceiling or even how different front desk design options look in the lobby.”
Augmented reality refers to placing computer graphics over the real-world environment. It differs from virtual reality in which the person is immersed in the digital world.
“AR is a tad more believable,” says Jennifer Suerth, vice president of Technical Services at Pepper Construction Co. in Chicago, a member of Chicagoland AGC. “You are seeing it at scale against something that is real.”
AR requires a model or a laser-scanned point cloud to cast a model image on reality, reports Josh Cheney, from Autodesk Construction Solu-tions in Portland, Oregon, a member of multiple AGC chapters. Models can be created in Autodesk Revit or Navisworks, and Autodesk BIM 360 keeps current files and models available to all stakeholders. Cheney reports that subcontractors as well as general contractors are experiencing benefits from AR.
As more projects use prefabrication, Suerth says, she believes that will lend itself to greater use of AR.
“The pieces are going to fit together, so you can snap everything into place,” she says.
Thornton Tomasetti continues to research various applications of AR, reports Vladimir Gluzov, a Boston-based associate of the firm, a mem-ber of multiple AGC chapters. The company has used it with tablets and iPhones, head sets, and special screens and AR glasses, which Gluzov believes have the greatest potential.
“The benefit of AR technology is the ability in real time to impose a virtual model on real-world objects and allow the user to virtually pre-view potential solutions,” Gluzov says.
“The architecture, engineering and construction (AEC) industry greatly depends on the successful coordination between various disciplines, and the implementation of AR technology can improve this collaborative process,” Gluzov adds.
Pepper deployed AR on a casino project to install a “Die Wall,” a counter with built-in betting machines. Subcontractors used AR to ensure not only the construction would go smoothly, but also future maintenance access would be guaranteed.
“Being able to understand the access and envisioning things is critical,” Suerth says.
During a higher-education project, McCarthy used AR after installing about 150 post-shoring, metal columns in a lower-level mechanical space, supporting the structural deck above. However, crews needed to install the mechanical equipment around the metal posts, which were not on any drawings or in the model, because it was temporary work.
With the model in an AR headset, McCarthy determined how to get some equipment into the space, skirting around the posts.
“AR was a way to reduce risk from potential schedule impacts,” Patton says. “We were able to install about 30 percent to 40 percent of the equipment in the space prior to the shoring being removed.”
Once the shoring was removed, McCarthy finished the mechanical installation with no effect on schedule.
Thornton Tomasetti generated several AR experiences by converting a large Revit model of Yale University’s new residential campuses in New Haven, Connecticut, into holograms for internal review.
On a healthcare project, Pepper needed to begin installing equipment as other crews were demolishing parts of an existing building. 3D co-ordination needed to be complete prior to verifying existing conditions, as the schedule did not allow for waiting on laser scan information to get started. Instead, the mechanical, electrical and plumbing coordinator walked the site with an AR headset to visualize existing conditions against the model to identify any conflicts, so they could be re-coordinated quickly before work was starting to be installed.
When adding a new building at a hospital campus, McCarthy had to connect the new structure to an existing central utility plant. It identified clashes early on in the BIM model. The routing in the construction documents worked inside the building but not outside, because existing equipment interfered with the plans. The mechanical and electrical contractors came up with a few routing options, but the facilities director at the health system was concerned about future maintenance.
To select the best routing option, McCarthy loaded the three options in AR headsets, so everyone could review the various options on site within the existing facility, including how close it would be to catwalks and existing equipment.
“Deploying AR worked out well in this application,” Patton recalls. “We had to make some minor tweaks at the end, but everyone was pleased with the final selection and it helped us make a quicker decision to keep the project moving forward.”
Additionally, McCarthy has used AR to show a healthcare client’s staff how a new tower would be constructed between three existing struc-tures and what effect it would have on the immediate surrounding campus.
“The benefit of AR technology is the ability in real time to impose a virtual model on real-world objects and allow the user to virtually preview potential solutions.” ~ Vladimir Gluzov, Thornton Tomasetti
“It aided a large group of nonconstruction stakeholders with their understanding of our jobsite and its impact to their campus, where we were at in the schedule and what the final product would look like,” Patton says. “It eased a lot concern for a group that was important to our client.”
Physicians, nurses and hospital staff also can use AR to review spaces, like operating rooms and patient rooms to make recommendations about locations of electrical outlets, placement of equipment or a cabinet.
PERFORMING ARTS CENTER
Electrical systems in a theater present challenges for contractors, with low- and high-voltage systems, stage lighting controls and sound sys-tems. Power cannot run too close to sound controls. McCarthy had used clash detection in the 3D model but knew there might be field adjust-ments.
McCarthy loaded the BIM coordination model into an AR headset and did a visual walk through of the cast-in-place concrete walls prior to pouring to validate separations between the two systems and coordination with final formwork and rebar placement. Patton called AR a “layer of risk mitigation.”
Pepper used AR to install studs in its Net-Zero Construction Trailer, starting with the short wall. As crews turned to the longer walls, the company had to keep readjusting alignment points.
“We successfully proved it’s doable, but I do not think it is scalable yet,” Suerth says.
While contractors are finding AR helpful, it has limitations. Suerth indicates the technology has not progressed quickly.
“Accuracy is a huge issue,” she says. “The tolerances are not tight enough.”
The model tends to slide the farther the person moves from the initial point. Pepper limits movement to 30 feet from the start point.
Gluzov also mentions the software and hardware limitations, such as a very small field of view, and underpowered processors and graphic engines. However, companies have begun processing AR graphics in the cloud rather than on the local device, and 5G technology could reduce costs and boost AR’s adoption in the AEC industry.
“The hardware and software are still in their infancy,” Patton says. “If the project needs a general understanding of how something may fit or look in a space, that is when AR can provide the best value for our projects, because it is a low cost and resource impact solution.”
However, Patton adds, “if the project needs a highly accurate visual, meaning you are dealing with small tolerances and very little room for error, AR is not the right solution today but hopefully will be in the near future.”
As for trying AR, Patton recommends caution and to talk with people who have invested in it, before jumping in.
“Innovation happens at the project level in the field,” Suerth says. “We have ton of use cases and excitement with AR. But it is still in its early stages.”