In 2013 there was not another hospital project in the country that was trying to do what Denver’s new Exempla Saint Joseph Heritage Project was attempting to do: Build the largest hospital under construction in the United States ($623 million, 831,327 square feet, eight stories) in less than 30 months.
How do you squeeze four years of work into less than 30 months? How do you take such an aggressive vision and turn it into reality? Prefabrication.
Bill Gregor, the executive for Mortenson Construction overlooking the project, remarked: “It was an extremely aggressive construction schedule. We get used to the term fast-tracked projects; the phrase for St. Joe’s is ‘hypertracked.’” The solution proposed by Mortenson Construction was extensive use of prefabrication at all the critical bottlenecks that occur during construction.
Is It Done Yet?
The Exempla Saint Joseph Heritage Project, which opened in December 2014, is a $623 million, 831,327 square-foot, eight-story, 360-bed replacement hospital. The job included 380 exterior wall panels that averaged 30 feet by 15 feet, more than a mile of multi-trade overhead MEP racks (250+ at 25 feet), 446 completely finished bathrooms and 400 patient headwall assemblies.
The exterior skin was the key to everything. As soon as the precast forms were removed from the floors above, the bearing angles were lifted into place and welded off to the embed plates. Then panels were set one after another. “Boom!” Twenty-four set this day. “Ouch!” Forty mile per hour winds the next day—can’t set. No problem. “Bam!” Twenty-six set on Saturday. You get the picture? Nothing was stopping the people of South Valley Drywall, Inc.
Davis Partnership and H+L Architecture provided design services for the new Saint Joseph replacement hospital in 2010. ZGF was selected as the design architect, and Mortenson Construction was the construction manager/general contractor. A scope that included the air/moisture barrier, continuous insulation, fiber cement panels, brick relief angle and brick ties for the first eight floors was the responsibility of AWCI member contractor South Valley Drywall, Inc., headquartered in Littleton, Colo. For floors 4 through 8, South Valley Drywall’s scope included the masonry backup exterior wall panels. Their work started in January 2014 and when it was finished at the end of July, South Valley Drywall had logged in more than 98,000 man-hours.
How did South Valley Drywall do it? Great planning and collaboration at an early stage of the project. Fred Pax, AIA, senior associate, said, “The exterior wall panels were done in conjunction with South Valley Drywall acting in a design-assist role. Davis Partnership brought to the table concept and performance criteria while South Valley contributed constructability expertise and specific product knowledge. This collaboration resulted in a high performing, cost effective wall system that was able to be erected in a record short period of time.”
The enclosure system is comprised of masonry, curtainwall, metal panels and punch windows. By design the panels could be lifted either by tower crane from overhead or below the cast-in-place tables on floors being poured two levels above by hydro mobile cranes. Exterior panels wrapped each floor of the concrete structure as it was built allowing interior work to begin immediately. To maximize efficiency, every element possible was included on the panels. The engineered cold formed framing came complete with pick points, fluid applied air barrier, spray foam insulation, continuous insulation, pre-installed brick ties and structural galvanized angles cleverly designed to weld to knife blade extensions at the framing.
The coordination of the install was much like a well-choreographed dance. Layout and panel stops coordinate the placement of each pre-designated panel. Fabrication drawings and quality control forms accompany each panel, from the panel designer through its install, to ensure compliance in the design. Back out coordination and window install continue within hours of the panels being attached to the superstructure.
Do the Math
In three months, from Jan. 17, 2013, to April 15, 2013, South Valley Drywall installed 84 percent of the exterior. In five months a total of 380 panels were installed to complete building enclosure on the largest hospital in the United States. Brandon Bergholz, enclosure project manager for Mortenson, explains it like this: “Twenty-six panels at roughly 30 feet by 15 feet. Do the math. The speed is incredible. The quality is phenomenal.”
In addition, South Valley Drywall was asked to install 3,600 sheets of fiber cement panels and two miles of extruded aluminum reveals. To accomplish this South Valley utilized their expertise in BIM to overlay the exterior elevations with the preplanned grid. Ninety-five percent of the material was precut off site, transported in bulk and then installed to hit the small schedule window allowed by Mortenson.
This incredible project combined the efforts of many dedicated professionals working in collaboration. We have been reading about prefabrication for more than 15 years—it is here, and it works. The Exempla Saint Joseph Heritage Project is a shining example of getting it right.
Project Data
Building Area: 840,000 square feet
Project Budget: $623,000,000
Construction Budget: $360,000,000
Project Delivery Mode: Integrated (CM/GC)
Design Started: March 2011
Design Completion: April 15, 2012
Construction Started: July 2011
Construction Completed: September 2, 2014
Contractor: Mortenson Construction
Source: www.healthdesign.org
