BY JOSH LEVY, HUSCH BLACKWELL, A MEMBER OF MULTIPLE AGC CHAPTERS
Building Information Modeling (BIM) is one of the most prevalent innovations in the design and construction industry over the past 20 years. It began as a more efficient production tool for design teams to deliver drawings but has grown to encompass nearly every project team member involved in the design and construction of a project, including the owner. The value of the digital representation of the project can extend far beyond the delivery of the project and into the management of maintenance, available space, inventory and future renovations and expansions.
For construction teams, the predominant value of BIM is to marshal the expertise of the specialty trade contractors to validate the architect/engineer’s design intent and produce a constructible project. This involves a thorough review of the specific products and materials to be used so a specialty contractor can offer suggestions and confirm any necessary changes with the design team. As each specialty system is individually validated for technical accuracy, each specialty system can simultaneously be validated with all other systems to ensure each component will fit inside of a wall or above the finished ceilings. Hundreds, if not thousands of digital conflicts, also known as clashes, are not uncommon to uncover during this validation process.
Resolving these clashes using a 3D model is certainly less expensive than discovering them after the materials have been fabricated, delivered and partially installed. As with any emerging technology, however, implementing BIM on a project can also create unintended challenges that can erode the benefits of BIM.
WHAT IS BIM?
When a patient in a hospital bed looks up, he or she sees a clean grid of ceiling tiles. Hidden above the ceiling is a complex network of specialized pipes, tubes and cables that provide the appropriate electrical, mechanical and plumbing utility services throughout the medical center. The uninitiated cannot begin to fathom the effort it takes to successfully design, coordinate and install these systems amidst the ever-present potential to run out of available space above the ceiling if not properly coordinated in advance. In a variety of ways the industry has sought to avoid discovering clashes in the field, when they are most expensive and disruptive to resolve. Prior to BIM, it was common for the specialty contractors to overlay their specific system drawings on a light table, in an effort to discover clashes shown at the intersection of two-dimensional lines. This old school approach was inefficient, imprecise and never really achieved consistent results — a project would be lucky to catch 50 percent of the conflicts with even the most experienced personnel. BIM brings the light table into the next century.
WHY USE BIM?
Architecture and engineering firms first adopted BIM to avoid making documentation errors when their production team sizes increased to meet critical deadlines; the confusion caused by incorrectly referenced details that were prevalent in a set of construction documents many years ago is far more rare today because of BIM.
Construction teams have also made significant investments into adopting BIM with the promise of being able to validate the design intent and enable efficient installations. BIM allows the contractor and its specialty trades to collaborate within a common 3D model while still maintaining control of their own scope of work. Construction teams use the ‘contract documents,’ comprised of the stamped drawings and specifications prepared by licensed professionals, and construct their own 3D models of their individual scopes of work.
Prior to BIM, the preparation of a system-specific shop drawing was intended to confirm that the specialty contractor was validating the design intent by reviewing details such as pipe sizes, pipe spacing, insulation requirements, required slopes, and clearance requirements for equipment. With a BIM-enabled project, having a specialty contractor review these same details is still a critical quality control step, but the difference with BIM is that the result is a 3D model rather than a 2D drawing.
WHAT TO WATCH OUT FOR
While BIM can resolve many traditional construction challenges, it can also create new issues if the team is not rowing in the same direction.
Out of the starting gate, the project’s team members need to be sure that all of the parties involved in the project have sufficient BIM capabilities. The level of sophistication among design, contractor and specialty trade firms in any market can dramatically vary.
A successful BIM project begins with a clear understanding of how the design models will be contractually treated. There is often clear contract language that states that any BIM provided to the contractor is not to be considered part of the contract documents and the models are to be used at the contractor’s own risk. It is also rare for a contractor to receive the design firm’s models without having to first acknowledge a digital model waiver of some kind.
On the surface, contract language that excludes BIM as an official contract document may appear to restrict the benefits that BIM can offer on a project. However, in practice, issues discovered using BIM simply need to be reviewed and presented to the owner and architect and engineer in terms of the information on the drawings or in the specifications. To illustrate the point, consider a design model that includes a drainage pipe that is required to be sloped by the specifications. This drainage pipe would still need to be sloped, even if the architect and engineer did not properly depict the pipe with the appropriate slope representation.
With the foundational understanding of how BIM will be contractually treated on the project, the contractor must then communicate the expectations to its subcontractors and ensure that they each have adequate resources to participate with BIM.
The biggest challenge to a successful use of BIM arises when the contract documents have true design deficiencies — defined here as simply missing significant equipment, frequently conflicting specifications and/or excessive areas where the MEP systems do not have a fighting chance to fit inside the walls or above ceilings. Most contract documents include language that describes them as being diagrammatic. The spirit of this language respects that the contractor (or their specialty trade partners) knows the most about the products being installed and how best to perform the installation. The reciprocal understanding is that there would be diminishing returns for the design team to ensure a best-fit placement of every pipe, as it is not the designer’s scope of work to be familiar with the minimum distances required between specific pipes in order to install a system.
We have seen contractors and their specialty trade contractors submit claims that fall into two general categories:
1. Excess costs from spending too much time on BIM coordination because the architect’s and engineer’s contract documents are allegedly poorly prepared; and
2. Change order requests to provide the necessary deviations from the originally documented design that are allegedly more comprehensive than simple coordination adjustments. There is a palpable gray area between a specialty trade’s need to adjust portions of a system to resolve clashes versus the need to relocate a system with significant additional time and material to achieve the design intent.
As facilitators of the coordination process, the contractor tends to tread into that vast gray area because offering solutions will often result in faster responses and stronger team relationships. A full-court press to redesign a few areas certainly works out in the Contractor’s favor when there are a limited number of occurrences. The architect and engineer team usually appreciates the construction team’s analysis of the design intent and the suggested modifications to the design as these suggestions limit the effort required on their side to revisit a portion of their design that may have been overlooked.
For a specialty trade contractor, knowing about having to add a few additional fittings prior to installation is far less expensive than slowed production rates or rework costs if a clash were discovered at the time of installation. But when these model-coordination efforts proceed without change management documentation, expectations of the owner and architect and engineer team may be unfairly set. The construction team’s willingness to resolve the first, second or third complex issue as a courtesy could make it difficult to request compensation for other significant changes that may begin to mount. By the time of the 20th issue, often with many more floor levels yet to get through, it will be more difficult to backpedal and claim that the project is beyond the reasonable expectation of time and materials needed to coordinate the drawings that appear to be of a lower quality. At that point, the contractor and specialty trades may already be too deep into the “no-good-deed” trap that they walked into. There may be little left for the BIM team to do other than continue to facilitate the coordination process with an increased level of input from the architect and engineer team and a tally of costs to resolve with the owner.
RESOLVE THE GRAY AREA
How do you emerge with a successful BIM program? The solutions may not be all that different from where programs are right now. Contractors and their trade partners need to find vehicles to document the first encounters of areas requiring re-design activities. If there is a deficiency of information, the RFI is an adequate vehicle to request the missing information. If the deficiency is more nuanced, some contracts require notification to the owner upon identifying where the design intent cannot be met. This notification requirement can be used as a vehicle to log deficiencies in the design and document the iterative feedback from the architect/engineer team in order to limit the time spent mocking up potential solutions. They can decide whether the contractor’s time would be better spent moving on to begin the coordination of other areas while the architect/engineer team revisits an alleged oversight in their design intent or provide direction to the contractor as how to resolve a conflict. This allows the owner and the architect/engineer to quickly determine if the design intent is flawed, keep track of how a conflict was resolved, and remain aware of occurrences of when excessive coordination is required.
Even though BIM might be new to a project team and offer new ways of discovering and resolving issues on the project, BIM does not require an overhaul of traditional project management and change management protocols as BIM is not uprooting how the industry delivers projects. BIM will continue to assist in speeding up how we uncover and resolve conflicts in a project, but fair protocols to evaluate claims remains the key to a successful BIM implementation.
Josh Levy is an attorney with Husch Blackwell, a member of multiple AGC chapters.