The Four Levels of BIM
Taking virtual design and construction to a higher level
A few short years ago, the use of building information modeling (BIM) was largely the domain of only the most sophisticated, forward-thinking and, some would say, well-financed project teams. Today, BIM has moved further into the mainstream and is being touted as a “transformative evolution” in the industry. For all the buzz, one thing is clear: Not all BIM is created equal. An early BIM adopter, DPR has always viewed technology as one key piece of a much larger puzzle when it comes to extracting the greatest cost savings and building the most value into a project.
Equally essential is the collaborative process, in which an integrated team is involved from cradle to grave designing, building and refining an information-rich model that goes far beyond the surface capability of 3D modeling and visualization. Operating at a “higher level of BIM,” multi-disciplinary teams collaborate to virtually design and construct the entire project before the first shovel hits the dirt, adding in more details to the model and thus increasing the level of certainty—and overall value—during construction.
Two San Francisco Bay Area healthcare projects, using DPR’s highest level of BIM within an integrated approach, have already netted noteworthy results prior to breaking ground in October.
The 250,000-sq.-ft. Patient Care Pavilion for Alta Bates Summit Medical Center, a Sutter Health affiliate, consists of an 11-story tower and rooftop utility plant being constructed on a 1.5-acre site in the middle of a fully functioning urban hospital campus. Once complete in early 2014, the tower, which also includes two stories below ground, will house 238 medical/surgical and acute rehabilitation beds.
The project is being delivered using a 12-party integrated form of agreement (IFOA), a relational contract in which the owner, architect, general contractor, and key design consultants and trade partners are co-signatories, forming the core integrated project delivery (IPD) team. The team is also making extensive use of Lean construction processes in conjunction with BIM for quantity take off, model-based estimating, self-perform work detailing and tracking, mechanical/electrical/plumbing (MEP) coordination, constructibility analysis, total station integration, and site logistics planning—all of which, according to DPR’s Peter Lockett, are resulting in a “better coordinated project and providing more value to the owner.”
For example, DPR, along with the architect, structural engineer, and steel and rebar contractors, modeled and coordinated the tower’s superstructure and exterior skin, resolving more than 4,000 clashes to date. The team also conducted a cost study based on the top 16 clashes that would not have been identified prior to onsite construction and estimated a more than 9 percent return on investment on the exterior skin scope.
“We also laser scanned the site, and the results produced an eight-inch dimensional difference between the team’s original model and the actual size of the site,” said Lockett. “By catching this early, our team was able to adjust construction drawings during the permitting process, potentially saving an estimated $500,000 in future change orders.” This adjustment was also critical because the tower, once complete, will be attached to neighboring buildings on three different sides and seven floors.
In addition, the team has identified savings of more than $2.2 million per floor, more than $18 million total, based on the 24,000 clashes it resolved using BIM to coordinate MEP, fire protection, architectural, structural and equipment scope.
The $1.5 billion UCSF Medical Center at Mission Bay project in San Francisco, also scheduled for 2014 completion, entails design and construction of a 289-bed, 635,000-sq.-ft. hospital and 200,000-sq.-ft. outpatient building along with ancillary facilities. Selected through a “best value” process, DPR, along with the owner, architect, project management consultants, and numerous engineering firms and subcontractors, established a virtual organization to develop a fully integrated BIM of all systems, studs, seismic supports and backing during preconstruction.
“The objective was to produce a much higher level of predictability around the budget, schedule and quality,” said George Pfeffer of DPR during a webinar for Architectural Record in September.
To foster optimum collaboration, the owner established the Integrated Center for Design and Construction (ICDC) on site in May 2009, 17 months prior to groundbreaking. The massive project was broken down into 25,000-sq.-ft. segments, with systems teams working in parallel to design and create the detailed BIM.
According to architect Ann Killeen of Anshen + Allen, a part of Stantec Architecture, a primary goal was to design a sustainable facility targeting Leadership in Energy and Environmental Design® (LEED) Gold certification. Using BIM, the team has achieved a design to meet LEED Gold standards, producing a more accurate energy model that allowed a significant reduction in the size of air handling units, using 50 percent less power than the average U.S. hospital.
Additional successes include the elimination of an estimated 11,000 clashes that had the potential to be requests for information (RFIs) and reduction and elimination of excess material, including some 3,000 linear feet of conduit and 7,000 pounds of ductwork.
Combined with the integrated approach, this use of high-level BIM has resulted in impressive bottom-line results. J. Stuart Eckblad, director of Design and Construction for UCSF Medical Center, estimates savings of around $200 million to date. “The scope of the project remains the same, and the quality remains the same. Having designers, contractors and subcontractors participating in the design, evaluating ideas collectively, and collaboratively looking at different options leads to optimal results,” he said.
Level 1: A tool primarily used to communicate design intent and help owners evaluate alternative designs at the beginning of a project and visualize an end product.
Level 2: Models created by design teams that include mechanical/electrical/plumbing (MEP) systems at a higher level done during the coordination phase to reduce requests for information (RFIs) and changes in the field during construction, as well as site logistics.
Level 3: Includes detailed models created by MEP subcontractors that are merged with the designers’ models to produce fabrication-level MEP models. Level of detail also allows for very detailed 4D sequencing of the building process, 3D as-built models, and the ability to pull accurate quantity trends directly from the models.
Level 4: Integrates substantially more stakeholders into the process from the early design stage to provide input and review, test the constructibility, and determine the best materials and methods for design and construction, in accordance with the project’s budget, schedule and quality. Level 4 BIM results in the creation of a model that incorporates such fine details as seismic and gravity hangers, metal framing systems, and detailed models of components like rebar. These models can be used to produce permit documents and shop drawings, pull material quantities, produce accurate model-based estimates, perform cross-trade prefabrication, and produce actual installation drawings.