How BIM advances cost-saving planning and prefabrication
Building Information Modeling (BIM) is an evolutionary leap for the design and construction industry. More than 20 years ago, Computer-Aided Design (CAD) was touted to have the potential impact that we now foresee with BIM, but the profession adopted that early technology primarily as a replacement for drafting tools. BIM is transforming how we work, how we communicate, and how we construct. Two recent projects by the Columbus, Ohio, office of the international design firm NBBJ demonstrate BIM's potential to save time, cut costs, reduce construction waste, and design better buildings.
BIM in a nutshell
BIM is a technology tool at the minimum, but the potential exists for BIM to be an interdisciplinary coordination platform that bridges communication gaps between designers and builders. Most importantly, data-rich models can also be used as a key method of enhancing the integration of the design and construction industries. Designers develop a project in a 3-D digital environment with multiple engineering consultants-mechanical, electrical, structural engineers, for example-coordinating and collaborating in this environment. Many issues can be resolved in a digital world rather than in the field, where modifications can squander time and money. The opportunity now exists to build every project twice-first virtually, then on-site. BIM allows us to coordinate more effectively the first time, enabling the real build to be more efficient and effective. The parallel collaboration enhances accuracy, improves adherence to budget and schedule, and increases productivity.
St. John Providence Park Hospital
Completed in September 2008, the new seven-story, 500,000-square-foot St. John Providence Park Hospital is located on a 200-acre campus of woodlands and wetlands. The new facility is the anchor for the health campus serving the community of Novi, Michigan. For this project, NBBJ used BIM as a design tool, a rendering tool to produce presentations to the client, and as a documentation tool at the construction document stage.
During the course of design the construction market was struck with two inflationary events, Hurricane Katrina and a strong outflow of domestic building materials to support an overseas construction boom. Two of the biggest material deficits were steel and glass. BIM was beneficial to the design team and construction manager, Barton Malow, in helping the project compete with the domestic demands of these materials.
The model was also used to develop the project's structural, plumbing, and mechanical design work. The structural steel subcontractor was brought onboard early during the steel design process, and used the digital model during design to generate shop drawings. The design team used the contractor's enhanced model for three-dimensional shop drawing review, and the model was carried directly into fabrication of steel. Information was continuously (and efficiently) exchanged between designer and steel contractor, resulting in precision of both the shop drawings and construction documents. This process provided for timely decisions, quick turnaround on approvals, and the prompt delivery of steel to the site while adhering to the budget.
The design and construction of the exterior wall for Providence Park Hospital serves as another illustration of BIM's potential. Early in the design process, CGI, the exterior wall contractor, was included as part of the project team. The exchange of digital files between NBBJ and CGI jump-started the shop drawing process while simultaneously enhancing the architect's details.
The exterior wall was a prefabricated, unitized system. Modules of aluminum framing, glass, insulation, and other materials were fabricated in the contractor's shop, eliminating the need to install curtainwall framing stick-by-stick and glass pane-by-pane. This design-assist collaboration between NBBJ, the architect, and CGI, with the model as common vocabulary, led to a superior design, a 20% savings in the cost of the exterior wall system, and the elimination of eight weeks from the construction schedule.
To sum up generally, price escalation and material shortages created two urgent needs: locking into materials costs and getting into the fabrication queue. The early integration of these subcontractors, paired with the time saved by the design team's sharing the building information model, contained the project's exposure to cost escalation and allowed for timely delivery of materials.
Miami Valley Hospital Heart Tower
Currently under construction, the 12-story, 480,000-square-foot Miami Valley Hospital Heart Tower (MVHHT) is scheduled to be completed in December, 2010. The first three floors will house diagnosis and treatment facilities, while the upper floors will contain acuity-adaptable inpatient rooms.
MVHHT's fast-track project schedule demanded a robust building information model that would promote simultaneous collaboration among the design team, consultants, constructors, and the client. Working within a single modeling platform, NBBJ's design team generated construction documents, presentation imagery, rapid prototypes, environmental studies, and design studies. The exterior envelope, interior architecture, furniture, fixtures, and medical equipment all were developed within the same modeling environment.
The integration of consultants, subcontractors, and the construction manager, Skanska Shook, into the design process inspired NBBJ to push BIM as a tool of prefabrication. A unique opportunity had presented itself during the design of the inpatient room. All 180 inpatient rooms are identical and same-handed, and BIM was used to develop the room design and to coordinate the complexity of medical systems. The model was an invaluable tool in understanding how the patient room could be prefabricated and for describing this process to the client and contractors.
The demising wall between patient rooms, which includes the patient bathroom, will be constructed in an off-site shop and installed as a modular unit, fully piped and gassed. The model also was used to develop a prefabrication approach to modular above-ceiling mechanical, electrical, plumbing racks, and demountable caregiver stations.
Similar to Providence Park Hospital, the unitized exterior wall system is being prefabricated and assembled off-site. Prefabrication is expected to result in improved construction quality, a shorter work schedule, and the reduction of waste. BIM was an inspiration for us to explore prefabrication initiatives and was an invaluable tool in determining its viability.
BIM involves much more than a change in software; it involves a significant cultural and behavioral shift, a different way of thinking about working with and relating to other parties in project planning and construction. Hopefully we are done with the days of designers tossing a set of construction documents to a contractor, who is seeing them for the first time. Contractors should be involved in the design through integrated processes like design-assist, and BIM can help in pulling traditional relationships upstream in this way. This makes the necessary cultural shift challenging-but essential.
Not long ago, escalating construction costs, spurred by soaring material prices, spiraling wages, and a hyper level of construction activity, created a pressing need for a more efficient, more cost-effective design and construction process. Now we are facing new challenges-the scarcity of capital is amplifying the drive to work smarter, faster, and more cost-effectively on healthcare projects. Healthcare clients are desperate to reduce costs as the economy demands efficiency. Competition within the healthcare industry is driving a race to market.
BIM can play a major role in achieving all of these objectives. Our industry needs to be transformed. Don't let it happen, make it happen. HD
Timothy M. Fishking, AIA, is a Principal and Ryan Hullinger is a Senior Associate with NBBJ, Columbus, Ohio.
For further information, visit http://www.nbbj.com.
Lessons and Recommendations
Engage your information technology (IT) team. Embedding IT staff within a BIM project team provides reciprocal learning opportunities. It is amazing how much insight you can gain from IT professionals, and how much they can learn about the practice of architecture. While traditional training classes provide a solid foundation on BIM, working alongside IT experts will enable you to more quickly maximize the potential of BIM and fully utilize the benefits of the technology.
Share what you learn. While behavioral change can be slow, capturing and sharing lessons should be rapid. NBBJ has found that sharing learnings in real-time, project-by-project, and between each of our offices, has accelerated the firm's transformation. BIM is now “table stakes” in the healthcare design and construction game. To evolve as a profession, our profession needs to share lessons firm-to-firm, industry-wide.
Learn from constructors. Many subcontractors have been ahead of the design industries on the BIM learning curve. Steel fabricators and mechanical contractors have been utilizing BIM effectively for directly linking shop drawings and coordination drawings to fabrication processes. Seeking advice from constructors builds both knowledge and relationships. The technology is pushing the profession, and the profession needs to push the technology.
Healthcare Design 2009 May;9(5):76-79