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Realistic renderings allow owners to understand the approximate quality level achieved by the intended design prior to any construction document activity. All images: Harley Ellis Devereaux
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Everyone in the construction industry is talking about Building Information Modeling (BIM).
Most architecture and engineering firms indicate that they are utilizing BIM to some degree on a
percentage of their projects. But what is BIM? Does BIM mean the same thing to an architect as
it does to an engineer, to a construction manager, to an owner, to facility maintenance
personnel?
Many factors are involved in determining the appropriate level of BIM utilization on a
project. Expertise and experience among team members can vary greatly. The functionality of BIM
software varies due to differences in product development, even within a single software
platform. Therefore, it can be difficult for an owner to understand an architecture and
engineering (A/E) firm’s capabilities and know what to expect in terms of BIM deliverables.
Where can the construction industry turn, to understand how each project should be approached in
regards to BIM?
This article will provide discussion on the benefits of BIM for the owner and how to maximize
those benefits, along with some Q & A to assist an owner in evaluating an A/E firm’s BIM
capabilities.
Why the “I”
For the purposes of this article, we will define BIM as a building model that is populated with
the associated intelligence of the components within it. This intelligence includes physical and
functional characteristics that are stored in a unified format to allow sharing of model
information between all project team members. For example, four walls shown on a plan are not
just a room in the building. Rather, the room has data that can define the number of people, the
heating and cooling loads, the lighting levels, and so on. In fact, the lines representing the
walls themselves have a composition of building materials with R-values and perhaps fire
ratings.
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When designing an auditorium, the team captured room, wall, floor, ceiling and furniture properties from the BIM-generated model. This data assisted in the acoustic simulation, allowing the project team to balance shape, materials, performance and cost early in
schematics.
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BIM is much more than just a 3D model. 3D is only one method of graphically displaying a
portion of the model’s physical information. Although it is common in the construction industry
to acknowledge a 3D model as BIM, without the embedded intelligence (information), 3D alone
falls far short of BIM.
BIM allows relevant information to be stored and accessed for analysis and decision making
while also allowing continual updating and refinement throughout the life cycle of the model.
Additionally, unified storage of information allows revisions to be made at a single location
regardless of how many times the data is displayed or shared. Unification of data storage
significantly reduces the errors of manual data transfer compared with traditional CAD and its
inherent repetitive manual methodologies. When effectively used, BIM can increase the efficiency
of the design and construction process and can accelerate the project schedule, which can result
in cost savings for the owner.
The BIM can reflect many aspects of the actual life cycle of a building. BIM can start at
pre-design and extend throughout the design, bidding, construction, occupancy and finally
decommissioning of the building.
One of the greatest values of BIM is the retention of information, with the opportunity for
continual evolution and communication of that data. Under this premise, the repetition of
requesting, parsing, assembling and transmitting information between team members at the various
stages of a model’s life can be greatly reduced or eliminated. This results in better
communication among team members and more timely responses to owner concerns or suggestions.
Sharing data for analysis and simulation is the foundation of BIM. The potential for
expanding the amount and types of project analysis is huge. Examples of this can range from
early analysis of building energy efficiency during conceptual massing, to
structural/mechanical/electrical load analysis during design, quantity take-offs during the
project bidding, shop drawing review/fabrication during construction, or even facility asset
management during occupancy.
Not only do these examples lessen the redundant tasks, but the owner receives more value by
allowing different analyses to be performed by transferring the data. This can be especially
true where multiple iterations of an analysis are repeated and refined at various stages of the
BIM lifecycle.
Here are some of the benefits an owner can realize from a BIM project:
- Afford a high degree of analysis of building systems, alternative materials, equipment, and
technologies which leads to more informed decision-making.
- Compress the time required to respond to owner’s questions, with a high degree of confidence
in the response.
- Flush out constructability issues.
- Reduce contractor uncertainty, which leads to a more accurate cost picture and more
consistent bids.
- Help the project team develop a practical and cohesive phasing plan.
- Reduce overall project delivery time during the design phase as well as the construction
phase.
- Increase overall accuracy of project documentation.
- Facilitate the analysis of sustainable design alternatives and cost comparisons.
- Make accurate and timely information readily accessible to team members at multiple
locations, including the construction site.
- Paves the way to improved asset management.
- Provides a mechanism for improved building and equipment maintenance.
Teaming methodology
The use of BIM is dramatically changing the way consultants are executing work. When utilizing
BIM, detailed collaboration happens sooner in the project life than it would with traditional
CAD. A significant amount of each team member’s work plan is shifting into the schematic design
phase.
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Structural engineering can benefit greatly from the coordination advantages of BIM. All images: Harley Ellis Devereaux
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A growing number of projects utilize some form of design/build project delivery, such as
Integrated Project Delivery. Integrated Project Delivery (IPD) is a method of project partnering
that utilizes the talent, experience and input of all team members to obtain the best results.
This method increases value for the owner by reducing waste and optimizing efficiency. The IPD
process can be applied throughout the life cycle of the project, from design and fabrication to
completion of construction. IPD results in shorter delivery times and overall project cost
savings. When a project utilizes IPD, the contractor or construction manager should also be
considered as part of the project team. Considering the potential of BIM, it’s plausible to see
BIM being coupled with IPD to further increase value and effectiveness.
Implementation of BIM software is a longterm commitment and should involve much more planning
than merely loading “out of the box” software and arranging training for the users. The use of
BIM changes the culture of project teams. Organizations that are embracing BIM will need to
rethink and retool their project delivery methods.
Committing a project to BIM does not necessarily mean that all team members are at the same
level. The make-up of a project team can range from multiple consultants each using different or
the same BIM or non-BIM software packages to a single, full-service firm where all disciplines
are using the same platform. The contractor or construction manager is a vital team member for
leveraging the BIM, especially on projects where design/build or IPD is being used.
Due to this high degree of variability, an owner should inquire about a team’s BIM
capabilities and the makeup of the project team. An owner should ask about BIM implementation
strategies used or being proposed by the project team. This will allow the owner to understand
how the team will utilize BIM to maximize the sharing and coordination of data.
To achieve the expected BIM results, owners should choose a project team that has adequate
experience, technical ability, and an implementation philosophy that includes their
objectives.
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A component library can be customized within BIM to eliminate repetitive tasks.
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Questions to ask before hiring team members
These questions can be used by owners during team selection to level the playing field between
potential service providers.
- First, ask yourself: What is my own definition of BIM?
- Ask each prospective team member to define BIM; this will help create separation between
those who understand and truly use BIM and those who do not.
- Which team members will use BIM?
- What portions/systems of the project will be modeled? Will existing systems be modeled?
- What systems will or will not have intelligence?
- Will the project team use out-of-the-box content or will they create custom content to
adequately represent building components and equipment?
- How recently has each team member implemented BIM?
- How many projects has each team member completed in BIM?
- What are some project examples of BIM and lessons learned?
- What type of standards has the team developed for delivering projects in BIM?
- Have any or all of the team members previously worked together using BIM?
- Will the project use single or multiple models? How often will they share models for
coordination purposes?
- Does the team’s process address the needs of facilities management?
- Will the team be utilizing design/build or Integrated Project Delivery?
Each of these questions can also be asked from the “who/what/when/why” perspective. It can be
very important to understand “why” someone has gone down the path of BIM, “how” they have chosen
their specific direction, “when” they started their implementation and “who” has
influenced/assisted them in finding this path and direction.
Delivering the benefits
BIM can be described as the virtual construction of a building or a digital building prototype.
Traditional construction documents are only one output that can be derived from a BIM.
Non-traditional deliverables, such as 3D coordination views, are visual aids that can
dramatically improve communication and understanding of the proposed building and integrated
systems. This is particularly true during design if the owner’s internal team consists of
individuals who are not familiar with reading traditional 2D drawings. Furthermore, coordination
and review can be accelerated by the owner’s internal team, as well as among the project team,
bidders and contractors through the use of these tools. In the past, a picture was worth a
thousand words. Today the views and information available in BIM is exponentially more
valuable.
Graphically, a host of other enhanced deliverables can be furnished during design, bidding
and construction. Examples include, but are not limited to, photo-quality renderings,
fly-through views, isometric views, sections and elevations anywhere that it is necessary to
clarify design intent, and color enhanced views.
Extending beyond the available graphical deliverables, BIM also provides the opportunity for
sharing of non-graphical data from the model. This could include specific items such as area
take-offs, quantity take-offs, fixture schedules, panel schedules, air change rates, load
summaries or other system analytical summaries.
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When information is entered once into the model by a project team member, the engineering team can review and use the real-time data for analysis of each system. For example, the mechanical engineer can review the building performance data, inputted by the architect, to analyze the building heating and cooling loads. The engineer can review duct sizing criteria, pressure drops in duct systems, or check for compliance with air change rates.
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For example, wouldn’t it be better and more efficient for the sheet metal contractor to use
the BIM for final construction coordination and fabrication instead of redrawing the systems?
BIM allows the opportunity to reduce redundant tasks. During design, it could also encompass a
more broad-based exchange of data like exportation of analytical data, interdisciplinary linking
of models, or transfer of the model itself. For example, the building envelope performance can
be taken from the model for HVAC load and energy analysis.
Since the use of both BIM and IPD are developing fields, contractual and functional issues
exist.
Contractual issues and non-traditional deliverables
It should be noted that although extensive information may be contained within the BIM-generated
model and be readily available, the legal issues regarding liability of its completeness and
accuracy will depend on the contractual relationship of the parties involved.
The AIA has released a document named E202 BIM Protocol Exhibit and the AGC has co-drafted
ConsensusDOCS 301: BIM Addendum to help guide this contractual relationship. Additionally, there
is no accepted industry standard way to compile the information. Schemas are available (IFC,
GBXML, etc.) but they are not fully supported in all software packages. Hence, full
interoperability and cross-platform data exchange is still a work in progress. Overall, certain
aspects of the construction and A/E industries are proceeding with caution with respect to
sharing of information between separate entities while others are openly embracing it.
The traditional methods of project delivery are evolving into methodologies of BIM and IPD.
Where an owner is requesting a consultant to provide non-traditional deliverables, they may be
expected to provide some level of release of liability or indemnification in order for the
consultant to meet the requirement without voiding their professional liability policy.
To understand what non-traditional deliverables might be available to an owner from their
project team the following questions should be asked:
- What deliverables will be furnished by the team under basic services?
- How will these deliverables be made available during each phase of the project?
- How will they be used to benefit the owner and the project?
- What additional items are available at the option of the owner and what are the associated
costs? (radio frequency equipment tagging, associated facilities management data, etc.)
- To what extent will BIM data be used for analysis?
- What automated processes will the team use for analysis of BIM data?
- What software will be used by each member of the project team?
- What BIM data will be shared between the project team members, contractor and owner?
Special benefits for various tasks
BIM offers multiple opportunities for coordinating work and elimination repetitous labor. For
instance our firm has used it in combination with Integrated Project Delivery for structural
engineering. The owner, engineer, contractor and fabricator recognize immediate returns when
using IPD. When all of the various team members on a project work together (even if they are
from different companies), and share information electronically, everyone benefits.
The most notable benefits are that the information exists only once and the potential time
savings that can be realized during the construction phase. The time savings is a direct result
of sharing the structural model with the fabricator. The shop drawings are then started earlier
and at an advanced stage. Electronic mill orders can be generated, and quicker estimates are
generated for budget control.
The last phase is to review the structural shop drawings electronically. The engineer and
fabricator transfer models electronically back and forth. Additional time savings are achieved
here with the elimination of the mail, drop off, pick up, and making copies.
Electrical design can also productively use BIM. For example, during implementation of
Revit software, Harley Ellis Devereaux identified opportunities to increase quality and
productivity by customizing our component library.
- Working clearances were added for clash detection.
- Device elevation graphics were developed to eliminate redundant notation on architectural
elevations.
- Components were developed with adjustable parameters to minimize the content library
necessary to execute a project.
Customization can also be key in maximizing an owner's use of a BIM model. For example,
asset-identification parameters could be provided to allow an owner to schedule and track assets
for depreciation.
Regardless of whether the information is graphical or non-graphical or whether it is being
shared among the project team, the owner or other parties, the method and format of the
information needs to be coordinated for composition and compatibility. The owner may also
inquire about issues related to compatibility and interoperability to determine if the project
team will meet the owners expectations.
In conclusion, as the construction industry continues to evolve toward a more efficient and
more highly coordinated method of project delivery, an owner can and should take advantage of
today’s BIM capabilities and benefits. Through the use of BIM, more efficient processes can be
developed, better coordination can be achieved, project schedules can be shortened and overall
project costs can be reduced. An owner should be flexible, fair and respect the opinions of the
project team regarding issues that present themselves while the industry continues on the path
to complete integration.
The authors are on staff at Harley Ellis Devereaux, a multidisciplinary design firm
headquartered in Southfield, Mich. (www.hedev.com). They are: Michael F. Cooper, PE
(principal, mechanical engineering); Brett C. Gatti (CAD/BIM manager); Shaun I. Rihacek
(associate, architecture); James A. Corsiglia, PE (principal, director of structural
engineering); Kirk G. Pesta, PE (principal, mechanical engineering); and Timothy B. Reamer, PE
(associate, director of electrical engineering). A different version of this article previously
appeared in Technology Century, a publication of the Engineering Society of Detroit.