Many architects and engineers might reply that BIM is a three-dimensional design and drafting platform. Others might describe BIM as a design-coordination tool that can enhance efficiency and minimize project document errors and omissions. Some contractors might tell you BIM is a work-coordination tool that helps them avoid time and cost impacts through construction sequencing. Other contractors will insist BIM increases their ability to manage materials, bidding and changes to the work order.
Building owners and facility managers might discuss BIM as a facility operations infrastructure and life-cycle management database that is tied directly to the design documents. Construction managers, such as myself, would likely couch BIM as a data-rich project management tool. The list goes on.
BIM is many things to many people in our industry, but at its core, BIM is a multifunctional technology-based process for generating and managing building and project data during all phases of planning and construction.
BIM as Method
Like many practitioners in the industry today, I cut my professional teeth in the two-dimensional world of design and construction, using terms like bum wad, sepias, blue lines and Mylar. This pre-BIM world of plans, elevations and sections, and hundreds of pages of specifications describing design systems, materials and equipment required design and constructional professionals to visualize two-dimensional designs in an imagined 3-D world.
Hours would be spent overlaying and comparing plans to make sure geometries were accurate and details tied correctly to floor plans and sections, with many more hours devoted to studying specified products and equipment to ensure the real-life 3-D versions actually fit into place as planned in our two-dimensional design universe.
Coordination tasks were tied to one goal: making sure everything worked. We would make detailed comparisons of spatial programs within the plans and hold coordination meetings for mechanical system locations and routing to avoid clashes with structural elements and other building systems. Making a change would render many sheets of paper obsolete. I cannot count the number of documents I personally stamped as superseded or void.
Working within two-dimensional design technologies was tough, limiting and problematic. Even the most rigorous quality assurance and control protocols could not guarantee the absence of human error and oversight from the plans. In the pre-BIM world, these mistakes, regardless of how big or small, could significantly impact project schedules and budgets.
Understanding where we come from is vital to envisioning the direction in which we are headed. While not a panacea for the industry, BIM is likely a step in the right direction — one that promises to help our industry deliver a better end product.
Using BIM, architects and engineers can move beyond the constraints of two-dimensional practices and processes to a real-life world of 3-D design in which the building can be modeled in a continuous process as it is developed.
BIM models can be used in many ways: to examine elevations and perspectives or to analyze the construction process. I have expanded the model into the scheduling and estimating processes, and the servicing and maintenance life cycle of building infrastructures.
In addition to robust software solutions that support an interoperable informational database and the creation of models, this three-dimensional technological process is rooted in a distinct methodology that requires rigorous organization, practices and protocols.
Augmenting the 3-D design platform with dimensions of schedule, budget and life cycle yields a tool with six dimensions of information that has the power and potential to fundamentally change the methodology of our industry and project delivery. As a consequence, the roles and responsibilities of the owner, architect, engineer and contractor in the design process are evolving, and will likely continue to do so.
Changing the Delivery Process
In the old days, every player in the project-delivery process had a part. The owner hired architects and engineers to design a project. When design was completed, the owner hired a contractor to build the design and the architect and engineer provided support and oversight.
The owner collected all the operating and maintenance manuals from the contractor and the as-built documents from the designers. When the building was finished, the owner occupied the building and implemented a regular preventative maintenance program. In theory — and far from reality — everything was always where the as-built documents described and nothing ever broke down because it was properly maintained.
The BIM method uses a planning phase that allows architects and engineers to digitally design models in a manner that will create huge efficiencies downstream and allows the contractor and owner/operator to connect to the design model earlier in the design phase.
The owner can begin to develop an asset management approach, the contractor can begin to develop a constructability approach based upon the project objectives, and the designer can run spatial and energy usage models to maximize environmental efficiencies. They can coordinate the design across various disciplines and analyze the model to ensure everything works as it should before it is built.
The contractor can use the model to perform clash-detection analyses of systems during construction and to run construction-sequencing scenarios, looking for faster and cheaper ways to build the project. Subcontractors can prepare fabrication models and coordinate equipment and systems to match the installation location. The owner will usually task someone from the team or their own facility management staff to populate the model with product data including operations and maintenance information, systems and equipment and life-cycle expectancies.
The beauty of BIM? All of this is done three-dimensionally and all of the data resides in one model. The changes, in many ways, resemble the impact and influence the development of CAD exerted on the drafting table.
However, not everyone in our industry has embraced the technology, methods, processes and practices of BIM and the use of three-dimensional modeling platforms is met with hesitation and resistance in some segments of the industry.
There are many firms still working in the two-dimensional environment due to lack of client demand for BIM designs. Some designers, contractors and owners, who have a level of competence, comfort and assurance with two-dimensional designs, view a move into 3-D modeling as a big step and don’t want another change.
Even though the definition of BIM is limited to a management tool with the potential to improve the project delivery process and project quality, a failure to adapt and adopt runs the risk of putting you out of business.
BIM as Project Management Tool
Three-dimensional models provide a realistic visual representation of how a building comes together and how it will look on the site.
Using BIM and GPS coordinates, you can literally shoehorn a building onto the tightest of urban sites. Connect the model to programs like Google Maps, and you can see how it looks from across the street. BIM models help manage a given geometric shape and they also have the ability to hold parametrics within the given geometry.
The real beauty of BIM for me, however, lies in its capabilities as a project management tool, particularly when time and cost are applied to the three-dimensional models.
Augmenting a 3-D model with the fourth dimension of time, the project team can examine realistic virtual illustrations of the construction process. Integrating the critical path schedule — which connects the structural, MEP and architectural activity timelines — into the BIM model and running a timeline animation enhances the contractor’s ability to incorporate a higher level of detail into the constructability review and logistics planning.
The contractor can incorporate crane locations, laydown areas and other site-critical components into the model. As the critical path linked model is developed, the contractor can also examine the assembly process and use the critical path schedule to identify the potential impact on traffic and circulation.
The difficulty in constructing a timeline model resides in the development of the schedule into a set of tasks that can realistically demonstrate how the building will be constructed. Developing these animation models requires highly trained, organized, detail-oriented technicians.
Cost integration, the fifth dimension of BIM, connects the contractor’s estimate to the design model. The data embedded in the model can be used to calculate quantities of materials and specify the quality required to meet the basis of design.
The model can act as a realistic basis for, and representation of, the project estimate. As elements are identified in the design, the contractor can link the budget estimate to the schedule of activities (a cost-loaded schedule) and the data can be stored in the model. If design changes need to be made, the data can be used to assess the impact of changes in both the design and schedule.
Contractors can use the information integrated into the fully developed BIM model in the buy-out process, while bidding subcontractors can attain a higher degree of accuracy because the model links required materials parameters of quantity and quality. Once the buy-out is completed the data-infused model can be used for invoicing and progress payments.
Training for BIM
The catch with implementing any new technology, process or practice lies in learning how to use and apply it for optimal outcomes.
The combination of mentor-oriented and classroom-based methods allow untrained staff to develop into skilled users in a short period of time.
What keeps me up at night is our industry’s resistance to change, which is often based on a fear of the unknown. The National Institute of Building Sciences Web site is loaded with information about where we are heading as an industry. Just as there were those who resisted the evolution to CAD, there will be those who resist the move to BIM and its whole-building approach to design.
From my perspective, understanding what BIM is, what it can do and what it can potentially offer represents an opportunity for enhanced productivity, accuracy and profitability. When we become more productive, make fewer mistakes and deliver successful projects, I usually can get a good night’s sleep.
Gregory J. Offner, CCM, is vice president of AECOM Design in Arlington, Va., and a member of the Correctional News Editorial Advisory Board.