April 24, 2008
How BIM helped a hospital go green
By TODD BOVEY
Become one of the first hospitals in Washington to achieve a LEED silver rating.
This was a primary goal when MultiCare Health System’s Good Samaritan Hospital planned major expansions at its Puyallup facility. The $400 million project includes a new nine-story patient care tower, central utility plant and parking structure. The 300,000-square-foot patient care tower includes a main lobby, express services, inpatient nursing units, emergency department, surgery and operating rooms with a central sterile area, cardiac catheterization lab and interventional radiology, diagnostic imaging and loading dock.
LEED documentation requires close collaboration between various members of the design team, particularly architects and engineers. Being on the same software platform helps a lot.
Three-dimensional building information modeling software has been available for several years and represents a significant upgrade from traditional 2-D CAD tools. But many architects and engineers are just now switching over to the more sophisticated systems.
Good Samaritan illustrates the green benefits that result when they do.
Patient care tower
Architects wanted Good Samaritan’s patient floors to have access to daylight and the natural world. The building will include green roofs, which provide more pleasing views for patients than the typical cluttered roof.
The tower will also include light shelves at the exterior windows to shade the lower glass while allowing more natural light through the top of the windows. While these features promote a better healing environment, they are also considered green and will help capture LEED points. The light shelves were shown in the BIM model, which made it very easy for the mechanical engineers to understand them and include the effects in the HVAC cooling load calculations.
In a typical scenario, architects would prepare 2-D plans of the building and then pass them along to engineers for fitting in systems. Coordination would therefore take place in two dimensions on the floor plans and in building sections.
Only after a contract was awarded would the contractor put together a detailed set of large-scale coordination documents for the various trades involved. If conflicts arose over limited space, as they invariably did, change orders would affect both the schedule and total project cost.
The Good Samaritan Design Collaborative, a joint venture between Clark/Kjos and Giffin Bolte Jurgens, adopted a much wiser approach. They established a cooperative relationship with other disciplines and the contractor early in the project.
This integrated design approach allowed CDi Engineers, Sparling and ABKJ to offer input from the outset concerning their respective engineering specialties: mechanical, electrical and structural. It was the first time that most engineers on the team had used Revit, new software that takes BIM to a new level.
The contractor and major subcontractors were also included in the design team meetings. This process allowed for a greater, and earlier, understanding of the design intent for other team members, greatly simplifying the critical communication process.
Central utility plant
Take, for example, the hospital’s new central utility plant, which will be located across a busy intersection from the rest of the facility. Huge pipes 24 inches in diameter run between the central plant and the hospital. These chilled water pipes, along with electrical wiring, will run in an 11-foot-diameter utility tunnel under the street.
BIM was used to model the two building vaults on the ends of the tunnel and to coordinate the piping and electrical items within the tunnel. Coordination with existing piping in the street was required. Several alternatives for getting the utilities across the street were examined by the design team and the contractors.
The use of the integrated approach provided buy-in by all the design and construction team members long before groundbreaking.
Seeing how designs fit
BIM software lets designers create a virtual 3-D model of a structure. They can then extract the specific views and information they need.
For instance, users can click on a particular room and instantly see details like height, area, volume, walls, ceilings, windows and doors. Construction documents can then be created on the basis of this information. Although they look like traditional 2-D CAD plans, BIM documents also spell out materials and quantities required, making it easier to plan and manage construction.
Revit is described by its manufacturer, Autodesk, as the first “parametric building modeler,” meaning that changes in one design element or view are immediately altered in all other views. The original product has been expanded to target architects, structural engineers, mechanical engineers, electrical engineers and the construction industry.
“The great thing about the newer BIM products is that each discipline can see how diverse designs will fit together,” says Leslie Jonsson, a project manager at CDi Engineers.
“Everyone suddenly understands what the space constraints are. This saves time and money in construction, which is what green building is all about and explains why BIM can contribute to an extra LEED point for teams that collaborate through BIM.”
Good Samaritan Hospital is on track for LEED silver certification, an enormous triumph for the hospital.
LEED features will provide tangible benefits to the hospital, such as contaminant prevention, an improved healing environment and reductions in construction waste, water use and energy use.
The water use is expected to be reduced by 20 percent and the energy use is expected to be reduced by at least 14 percent compared with a conventional hospital. These reductions will result in large cost savings to the hospital.
The patient care tower opens in early 2011, and the parking garage is expected to open in mid-2009.
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