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Buckling Up Risks
The construction community and its
insurers should embrace 3D modeling to further reduce risk
on complex projects
Commentary by Richard H. Lowe
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Rick
Lowe
Attorney-at-law
Rick Lowe, a construction lawyer
in the Philadelphia office of Duane Morris LLP, is also
chair of AGC's PIAC BIM Forum Legal Subcommittee and
an active member of AGC's Contract Documents Committee.
Web site: www.duanemorris.com
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The argument in favor of using virtual 3D modeling as a way
to reduce risk for the construction community seems as simple
as the reasons to use seat belts. When seat belts became popular
in the 1960s, insurance companies offered discounts to encourage
their use to reduce the cost of losses in a crash.
Today, a similar technological leap presents itself in the
construction arena. With the advent of 3D modeling and virtual
"clash detection," the project team can catch potential
conflicts sooner and cheaper, with more cooperation from subcontractors.
A 3D model offers more specific design information than 2D
drawings. Given that the world is 3D and not 2D, how can that
additional specificity be a bad thing for project liability?
Despite the obvious benefits of clash detection, some designers
and constructors are leery of moving into 3D modeling because
they sense other impediments in the allocation of risk. Most
of those skeptics don't realize that the risks are no greater
(and sometimes smaller) in the 3D world than in the traditional
2D world.
Consider these facts. First, the 2D world is hardly free
from risk. Decades worth of construction litigation has proven
this point. Second, the use of 3D virtual modeling for fabrication
and construction is nothing new. Engineered projects (think
process-piping plants) have been using 3D modeling for decades,
and subs have been adding the third dimension in shop drawings-such
as spool drawings for process piping-for a long time. Those
projects aren't less complex or risk free.
Third, as a practical matter, the use of 3D modeling fosters
a broader collaborative effort, especially when the contractor
is invited into the process early. Design reviews and clash-review
meetings bring everyone into the same room, working to solve
a problem. This significantly reduces everyone's risk.
In Charge
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The $276-million Sprint Center in
Kansas City will be an 18,000- to 20,000-seat venue
designed to host major league sports, as well as concerts,
family shows and special events. Mortenson was selected
to serve as the construction manager-at-risk for the
new downtown arena.
Photo courtesy of Mortenson
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A concern from the design side is whether the architect-of-record
or design-builder remains in "responsible charge"
of design, as required by many state laws. That's based on
the faulty assumption that the line between design and construction
is blurred using 3D design, including fears that someone other
than project leaders can change the model without their knowledge
or approval.
That issue can easily be addressed by adopting a protocol
where all changes to the model must come from the designated
team leaders. They need to establish tight access controls
and an audit trail of additions to the model that clearly
identifies the source and date of all changes.
It is overly simplistic to assume that a single, "master"
model for projects exists. In fact, each construction discipline
maintains a model for its area of responsibility, and the
project leaders then use an integrated model that refers to
the 3D models for structural steel or mechanical and architectural
components.
The integrated model can be distributed to all parties to
detect clashes, but the only place where design changes can
be made is in the models of individual disciplines, not the
integrated model. When a clash is detected, a joint decision
is made about what needs to be adjusted to address the problem.
The architect moves a wall, the structural engineer changes
a beam, and the MEP designer adjusts ductwork.
Another assumption is that 3D modeling compels the project
team to include more detail than in a traditional approach,
thereby causing designers to move into a "means and methods"
arena, for which the contractor-not the architect-should be
responsible. That concern can be alleviated by everyone acknowledging
that the design team is creating no more than a design-intent
model. This has less detail than the construction-intent model,
which results from incorporating the contractor's shop drawings
and submittals into the design-intent model.
Differences
The difference in those two levels of detail in an integrated
model can be clarified by describing in the project specifications,
on a discipline-by-discipline basis, the level of detail designers
are responsible for and the level of detail for which the
contractor and its subs are responsible.
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Turner Construction Co. applies
3-D MEP coordination on many of its projects to prevent
clashes and conflicts from occurring in the field.
Photo courtesy of Turner Construction Co.
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We need look no further than the American Institute of Steel
Construction's Code of Standard Practice for Steel Buildings
and Bridges for a clear delineation between the structural
engineer's deliverables-specific information about the connections
the fabricator must detail-and the fabricator's deliverables-connections
based on that information. Although this delineation may have
been lacking in many traditional projects, 3D modeling does
not prevent project leaders from clearly establishing who
owes exactly which deliverables at what level of detail.
Some designers might also be concerned that 3D modeling compels
them to coordinate construction, which is the contractor's
responsibility. This concern, however, confuses two concepts.
The contractor must coordinate its subs, but the architect
must coordinate the various disciplines in the project design
so it can be built. Surely, there is no cheaper or more thorough
process to check constructability than doing a clash check
to determine if two or more objects will have a hard clash,
literally taking up the same space in 3D coordinates, or a
soft clash, where distances between objects are not large
enough.
In a 3D model, the contractor remains as responsible for
shop drawings and submittals as it was in the traditional
2D project. In addition, the parties should acknowledge that
the contractor still handles dimensions and quantity takeoffs.
That rule should apply even if the contractor uses takeoffs
prepared by the designers' software programs. Use of such
takeoffs is done at the contractor's own risk, standard procedure
for items like door schedules. In contrast, current software
packages may not be robust enough to calculate cast-in-place
concrete quantities. There is no reason for those practices
to change simply because the project is being 3D modeled.
Liability Protection
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Mortenson used BIM extensively during
design and construction of the University of Washington
Research & Technology Building in Seattle.
Rendering courtesy of Barton Malow
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Another concern of the design team is how its liability protection
may be diminished with 3D modeling. One doctrine that prescribes
a designer's duties to third parties is the "economic-loss
doctrine," which bars third-party claims for economic
loss in the absence of physical injury, but the analysis should
not change using a 3D model.
In either situation, the question is how foreseeable is it
that someone will rely on the designer's work. That analysis
should be no different whether the 2D plans are copied and
distributed to someone on the project than if a 3D model is
made available to the same person.
What if there is a glitch in the 3D modeling software where
the integration of individual discipline models is still a
relatively new technology? The project owner should bear the
risk of those glitches, provided the participants are adhering
to the protocol. After all, the owner hopes to benefit from
the lower costs of 3D modeling.
If an owner is unwilling to take on that risk, the project
team leaders must weigh the risks of a software glitch against
the existing risks that designers could fail to coordinate
drawings. From a practical standpoint, the risk of making
a drafting mistake in carrying a change from one 2D drawing
to another is greater than the risk of glitches in the model-integration
software going undetected until too late. With 3D models,
risks are reduced that the design of a specific component
is unexpectedly different than the typical design because
the virtual model can readily replicate the typical without
taking countless drafting hours to do it.
When all of these issues are analyzed, the perceived legal
risks in using 3D modeling melt away and are outweighed by
the obvious benefits of clash detection and greater project
collaboration. It should be only a matter of time before insurers
offer discounts to encourage clients to wear the clash-detection
"seat belts" of 3D modeling. Ultimately, the question
will morph into whether team leaders actually increase risks
by not using 3D modeling, much like not using seat belts.
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