As the concrete and steel of Davidson College’s New Academic Building (NAB) rise slowly to fill a 15-foot-deep hole behind Martin Science Building, the enormous structure is already nearly complete in cyberspace.
A collaboration of its construction partners is employing the latest in building information modeling (BIM) technology in a groundbreaking demonstration of the future of the construction industry.
BIM is being used on campus in construction of both the NAB and Davidson’s Vance Athletic Center expansion. The $74-million NAB and associated renovation of Martin Science Building will be 160,000 square feet and ready for occupancy in late summer 2017. The 50,000-square-foot Vance addition will be ready for occupancy in fall 2015.
The major partners in the projects are Shepley Bullfinch architects, Vanderweil Engineering, Simpson Gumpertz & Heger as the structural engineer, Rodgers Builders of Charlotte as construction manager, Davidson College, Mecklenburg County Code Enforcement and numerous subcontractors.
Traditional building design was reliant on two-dimensional drawings on vellum. Contractors kept their thick binders of design drawings on the job site, and lay one sheet of vellum on top of another to see how one building system affected another.
BIM replaces the traditional building construction documents with a computerized model of a construction project. Workers on the Davidson sites are accessing the building schematics as an electronic model on their tablet computers. “There will be zero hard copy plans on this job,” said Brian King, integrated construction manager for Rodgers Builders.
Instead of construction drawings, subcontractors will wield iPads and a software called Glue 360 to access an electronic, multicolored model of the building. Using video game-like finger swipes and taps on the screen, builders can move rapidly through an entire project, viewing any aspect at any scale and from any angle. They can zoom from a small view of the whole structure almost instantly to an enlarged view of, for instance, a single door handle.
But more than simply allowing “magic carpet” navigation, BIM contains valuable information about each piece of the project.
“The most valuable aspect of BIM is the ‘I,’ which is information,” explained King. ““BIM is essentially just a database of information that grows as you proceed and as the parties involved put more and more information into it. The more information that gets to the builders in the field, the better equipped we are to construct the building efficiently.”
For instance, a click on that virtual door handle brings up a palette of its properties. Those might include manufacturer’s name and link to their web site, part number, color, associated hardware, and designation of the subcontractor responsible for installation. In its fullest implementation, the BIM database can also manage the construction schedule, budget, and long-term maintenance costs of the job.
The software also points out trouble spots in cyberspace before they have a chance to arise in the real world.
Problems inevitably arise in the course of construction as different subcontractors make plans for their separate parts of a job.
“Construction projects traditionally follow a natural order,” said David Holthouser, director of facilities management at Davidson. “Sprinkler heads and sewer lines have to be in specific places, ductwork goes from bigger to smaller and light fixtures have to be spaced evenly down a hallway. You’d figure out who should go to work first and hope that crew would put things in the right spot. But that never happened. It was a huge burden on the building superintendent to coordinate the work of all the tradesmen.”
The new BIM norm in construction begins with the architects and engineers creating the basic plan (referred to as a “model”) virtually using proprietary software such as Autodesk Revit or Navisworks. Those models are passed on to members of the design team, including structural engineers, mechanical-electrical-plumbing engineers, and civil engineers, who populate the model with more detailed information about the job.
The leaders of subcontracting groups such as sprinkler, telecom, conduit, mechanical, and HVAC then access the model as they begin work on the building. The new system requires that subcontractors learn the Glue 360 software. King from Rodgers Builders has held a training session for them, and is offering continuing education and oversight as they become familiar with the new electronic tool. King noted that it is becoming mandatory for subcontractors to learn and know the software as a requirement of bidding and building projects.
The county’s Code Enforcement office also plays an important part in construction projects by assuring that they meet standards for safety of the future occupants. Recognizing the advent of a new era of high-tech construction, the Mecklenburg County code office is using the Davidson projects as pilot cases for a more efficient way of reviewing, permitting and inspecting construction projects. Code officials have been given the same access to the building models as everyone else, so that they can review and permit construction before it begins, and identify some potential trouble spots prior to installation. The goal is maximizing efficiency in design and construction, and passing all inspections the first time with few, if any, changes.
The code office has established an Integrated Project Delivery (IPD) team assigned to the Davidson jobs. Those team members will follow the job through to completion and conduct both plan review and inspections virtually, along with state-required on-site inspections. This team and service approach will allow for far deeper code enforcement involvement than on non BIM-IPD projects, speeding up the permitting and inspection process.
Holthouser explained, “In the old days the architect would finish drawings and send them to the code people. They would review all aspects of the plan to make sure it met code. In places where it didn’t, the reviewer would take out a red pen and write ‘revise and resubmit’ right there on the plan. It was an iterative, back-and-forth process until the reviewer was satisfied. Those revisions could go painfully back and forth forever.”
The new capability is expected to save a considerable amount of time formerly spent physically inspecting job sites. Because of the work done in the virtual environment, inspectors will arrive on site already intimately knowledgeable about the project as a whole.
“You spend more time building it virtually so you do things once, get them right, and they pass inspections the first time,” said Jim Bartl, county Code Enforcement director.
Bartl said BIM reflects an advancement in construction productivity similar to that enjoyed in manufacturing. He recalled: “In college I worked inside an old grimy, conventional 1960s-style manufacturing plant. That same manufacturing facility now employs robots in a space so clean you can eat off the floor, with lasers checking constantly to make sure everything is perfect.
“I’ve worked on construction sites for many years, and finally see that same type of modernity in construction as in manufacturing. Architects and contractors and owners now have a tool to build things virtually before they do it for real. They can integrate all the players, with everyone working inside the model on how to deliver the product as early and error-free as possible.”