Innovation through challenges with BIM
The Rush University Medical Center is the largest Perkins+Will healthcare project delivered to date using a BIM Platform. It is a 14-floor, $575-million, 806,000-square-foot building with three floors devoted to surgery, imaging, and specialty procedures. The upper floors contain 304 acute and intensive care beds, 72 neonatal intensive care unit beds, and 10 labor and delivery suites. Special considerations were made due to the complexity of the building, program requirements, and its scale to provide the team with the best possible working scenario. Early recognition of the interactive nature associated with successful BIM projects became the basis for planning. Our team of design professionals moved into a project site office to maximize the advantages of working in proximity with our extended team, construction managers, and client.
The site office, located at the medical center's campus in Chicago (figure 1), was equipped with the fastest and most robust desktop and network resources available at the time. Autodesk's Revit Architecture became the core platform for production. Our consultant engineers complemented it with Autodesk Revit Structure and Autodesk Building Systems as the core production applications used by Thornton Tomasetti, Inc., and Environmental Systems Design, Inc. respectively (figure 2). Custom training courses on the Revit Architecture Platform were developed and delivered by “just-in-time” Perkins+Will IT Design Applications staff to ensure a streamlined educational experience focusing on instruction for project-specific needs and requirements. Multiple software tools were introduced to aid in the process of multiple design iterations, clash/collision avoidance, visualization, analysis, coordination, project information management, as well as team communication internally and externally to the project office. Some of the most frequently used applications in our portfolio are Navisworks, 3D Studio Max, Ecotect, and Newforma. The Rush University Medical Center was among the first to use instant message type communication as a means for coordination.
Exterior ground view rendering at intersection of Harrison and Ashland Streets. Chicago, Illinois
Revit model of structural components. Models from all disciplines were merged for clash/collision avoidance in coordination meetings
Several months into production, the team expanded considerably. As the richness of information embedded grew, model size and application performance decreased. Despite the thoroughness of our planning, exponential team and model growth presented a multitude of challenges. Measures needed to be taken concerning team interaction, workflow, and the IT infrastructure foundation. Our mitigation strategies included model splitting, additional costly software and hardware investments, and the minimization of mixed CAD and Revit production environments. All of these approaches had cost and workflow implications revolving around increased model management. The application's scalability limitations-which the vendor wishes to avoid discussing and is not prepared to support-demanded well-timed discussions about drastic measures. To avoid losing the advantages of working in a well-coordinated single model, we wanted to delay further segmentation of our files for as long as was possible.
To overcome each challenge, we set out to innovate. We stretched the limits of the software and ventured into unknown territory with considerable amounts of calculated risk taking, ultimately leading to a success story that allowed us to convert those experiences into best practices and standards for this project, as well as many others in our firm. Building Information Modeling became a catalyst for improving our processes for building design. The following points are some examples:
Integrated design: In line with Perkins+ Will's commitment to of sustainable design, the new facility's energy efficiency generated much interest and concern. Our design team worked in conjunction with the MEP team to transform the exterior wall from the original all-vision glass to a much more energy friendly metal panel design. Primary design objectives considered thermal, visual, and acoustic comfort with minimum energy consumption. Our teams used several analytical software packages such as Ecotect, DOE/2, MIT's Design Advisor and HOMER to plug in parameters such as location, weather data, occupancy, wall dimensions, lighting requirements, equipment load, and temperature for energy performance simulations of different skin wall types. Having this information available for analysis allowed us to reach Rush University Medical Center's goal of becoming the first full-service green hospital in Chicago targeting for LEED Silver and currently tracking toward LEED Gold (figure 3 and 4).
Comparative analysis on monthly energy consumption by building envelope types
Energy analysis calculations based on multiple glazing options for the bed tower
Quantity take-offs/Budget tracking: Rush University Medical Center employed a “design assist” method of delivery for the exterior wall at schematic design by collaborating with curtain wall subcontractor, ASI Limited. The Revit model used in conjunction with Ecotect provided us with the ability to generate and study virtual mock-ups, and achieve a more economical and efficient final skin design. Material square footage take-offs were quickly extracted from the models, allowing comparison for budget estimates based on associated quantities provided by ASI Limited (figure 5).
Schedules with quantity take-off information present another view of Revit model as a database
Consultant coordination/Planning principles: Patient and staff safety were owner mandated and guiding principles for the project. Patient room standardization became a key strategy to meet this goal. Originally, the all-glass butterfly-shaped bed tower was designed to allow maximum flexibility in the layout of identical rooms by having a structural system independent from the base. A series of super-columns at the corners of the bed tower transferred loads to the foundation, 8-stories below, a dramatic move but also a very expensive one. Being able to maintain the butterfly shape and stay within budget demanded a collaborative process among our planners and structural engineers. Their interaction resulted in reduced costs without sacrificing programmatic requirements, design principles, and structural integrity. The computer model was vital to this collaboration. Senior Perkins+Will designer for the Rush University Medical Center, John Moorhead, says, “Building Information Modeling allowed us to quickly assess the visual merits/pitfalls of the design change. The traditional distinc
tion between 3D design and 2D technical was dissolved because the Revit model is the basis for both the presentation renderings and the construction documents. The entire team is using the same model files to do their work…interiors, medical planning, technical, and design.” (figure 6 and 7)
Design vignettes to study multiple façade options serve as virtual mock-up
Evolution of Rush University Medical Center through early design stages
Documentation/Life safety code compliance: The City of Chicago Building Code has restrictive 4-hour separation requirements that can limit the amount of floor area. To achieve the floor-plate size that Rush desired, our technical team proposed subdividing the floors into smaller 2-hour separations that met the spirit of the code but with simpler and less expensive construction. Embedding fire rating information for all partitions in the Revit models allowed us to clearly represent and coordinate changes. After many months of “kicking the tires”, Chicago's Committee on Building Standards and Tests was convinced with the aid of the graphics generated directly from the Revit model (figure 8).
Color-coded 3D life safety diagrams
BIM triggered major process changes, transforming the way we thought and worked. As design professionals, leveraging the value of BIM drastically facilitated our goal of meeting our client's demands with signature design, high standards of patient care, and respect for the environment in which we work. As IT professionals, support from BIM subject matter experts and state-of-the-art IT infrastructure was key. Examples of our proactive involvement include regular visits to the site for close project support, clinics, model splitting, and file management, etc. Regular support meetings were centered on the identification, nurturing and growth of professional design staff mastering the application toolkit, and taking ownership for each of the building model pieces. In its current construction administration phase, IT support primarily consists of ensuring adherence to good data hygiene and best practices for interaction with the general contractor. Our process benefited from IT professionals and the design team working in tandem through all stages of the project.
We planned strategically but still had to be nimble enough to react tactically to situations that the best planning could not anticipate. In retrospect, it is evident that the benefits clearly surpassed the challenges. Not so long ago many of us would have considered the use of BIM in a project of this magnitude and complexity as quite irrational and in some cases impossible. Today, for the exact same reasons, it is hard to imagine executing a project delivery without it. HD
Hilda Espinal is Director of IT Design Applications at Perkins+Will.
For more information, visit http://www.perkinswill.com.
Healthcare Design 2010 May;10(5):100-103