August 13, 2019
Nestled at the edge of North Carolina’s Research Triangle, an area famed for innovation, the popular suburban community of Cary consistently ranks among the nation’s most desirable places for active families. It is here that UNC Healthcare Panther Creek is embracing prefabrication to bring its new ambulatory surgery center online more quickly, addressing the growing community’s need for greater access to healthcare. By using a robust virtual design and construction program along with the use of prefabricated plumbing, electrical, and conduit materials, as well as tilt-up walls, DPR Construction is able to deliver the project one to two months quicker than if using traditional methods.
“The real story here goes deeper than the prefabrication itself. It was really about the modeling and coordination efforts done before we even stepped foot onsite,” says Superintendent Daniel Wrenn. “All penetrations, all hangers and embeds were already in place before we poured any slabs or decks. The day after we poured the deck, we were able to start the rough-in—in-wall and overhead. Normally, you’ve got weeks of layout and putting up your hangers before you can put the first piece of material up. Instead, our approach saved a lot of time.”
Modeling was instrumental in streamlining production of prefabricated materials off site, so when it came time to put the materials in place there was no question of placement or tie-ins. DPR crews were able to virtually tilt in the wall panels ahead of time, before fabrication, allowing them to identify any imperfections or misalignments in the embeds ahead of time. Additionally, laser scanning allowed for verification of embed placement on site. If embeds were even a couple of inches off, the information could be relayed to the project team and the trade partner for quick adjustment, eliminating schedule risks. Catching potential misalignments ahead of time creates significant time and money savings versus dealing with errors later in the field.
Modeling was also used to map out plumbing, electrical and conduit locations before these materials were fabricated. Copper pipes and fittings used in construction were tagged for specific locations for shut-off valves—all based on the modeling. Hard pipe is typically stick built in the field, with electricians bending pipe on site after boxes are roughed in. At Panther Creek, hard pipe was built off site according to the model. Electricians also traditionally install one stick of conduit at a time, but the modeling, coordination, and prefab efforts here allowed racks of 12 conduits to be installed at once. Fabrication work being done in the shop rather than on site cut down significantly on labor, accelerated the schedule, and reduced exposure to safety risks. “Prefab has been around for years,” said Project Manager Cameron Martin. “But these are new methods of employing it.”
Says Wrenn, “You couldn’t have done the prefabrication like our trades did without the modeling and bringing all the trades into the process. The trades used the Trimble system before the actual concrete was poured on any of the decks, and they were able to do the in-wall rough-in before the walls were studded.” Relationships with appropriate trade partners, such as plumbing contractor Environmental Air Systems and electrical contractor Cooper Electric, also helped in DPR’s success at Panther Creek.
Working under a tight schedule, DPR leveraged its relationships with important trade partners and brought its expertise in BIM modeling and coordination to the table to help deliver an excellent facility with cost efficiency and improved safety ever at the fore. The 96,700-sq.-ft. tilt-up medical office building, which includes a new ambulatory surgery center, imaging suites, pharmacy, and multiple medical clinics is scheduled to open in the fall of 2019.