Vertical expansion was always in the cards for the University of Pennsylvania Health System’s corporate office and support services building in West Philadelphia. Completed in 2019, the 10-story, 250,000-square-foot structure was designed for eventual overbuilding of a similar size. This planned addition was initially intended to house administrative staff.
But in the world of medicine, change can sweep dramatically. The university health system, nicknamed Penn Medicine, is one example. He played a key role in the research that led to the rapid development of vaccines against COVID-19. This fast-track effort also reshaped the priorities and timeline for the planned expansion of 3600 Civic Center Boulevard.
Stephen Greulich, Penn Medicine’s associate vice president for capital projects, explains that with an urgent need for more research and laboratory space, “we looked at how we could change plans and adapt.”
The project team had to keep the existing roof equipment online while building eight stories above and then transition to the new mechanical equipment so they could retrofit and demonstrate the old roof equipment and turn this area into a of laboratory
Photo courtesy of LF Driscoll
The key to speeding up overbuilding, he adds, would be to adopt a “lightweight” version of the project’s integrated delivery. Penn Medicine teamed up with Perkins&Will, the architect of the original headquarters, and contractor LF Driscoll Co. in 2022 to launch the planned $360 million, 217,000-square-foot, eight-story construction. Officials aimed to complete design and construction in three years, keeping the existing building occupied and fully functional.
Greulich explains that the “IPD light” approach provided the collaboration needed to accelerate the project while minimizing initial development time. Because both companies were well-versed in Penn Medicine’s projects and preferences, “we assembled a great team that we had a lot of confidence in, without the need for a learning curve,” he adds.
Chris McGinnis, project manager at LF Driscoll, agrees. His firm, which had just completed Penn Medicine’s 1.5 million-square-foot pavilion, a 17-story hospital, says that “everyone in design and construction was on board with the approach, even though that was very fast.”
The ability of some of the key trades on this project to transition to overbuild allocation helped the team quickly address industry supply chain issues. That allowed team members to make important decisions so construction could begin in early 2023, including ordering fixtures well before the superstructure was designed because the lead time was 60 weeks, McGinnis says. “We ordered steel with a very basic schematic drawing set as it would take nine months to get it on site,” he adds.
Allan Horton, senior project manager at Perkins&Will, adds that early input from subcontractors, constructability reviews and discovery sessions helped the team move forward and stay in sync. “If there was a change, we knew and communicated it right away,” he says.
The transition from the existing mechanical systems to the equipment located in the new mechanical attic involved almost a year of planning to develop and coordinate a complex step-by-step changeover strategy, which is currently scheduled for mid-May.
Photo courtesy of LF Driscoll
From offices to laboratories
While the structural and building systems of the existing building provided a literal and figurative basis for the superstructure design, the shift in program from offices to wet labs and support spaces required multiple changes. The need for at least 4 more feet of floor-to-floor height had a ripple effect on everything from structural load and occupancy calculations to maintaining the continuity of the building’s exterior appearance.
Similarly, the floor designs required rethinking to fit within the extensions of the core and axis elements of the existing building. “We made some adjustments to make it work while maintaining the flow and adjacency between the lab plant support areas and the researcher workspaces,” says Maha Sabra, CEO of Perkins&Will. “It was also important to organize spaces to give access to daylight whenever possible.”
“There were very few cranes on the planet that would allow us to do these things without having to be tied to the existing building.”
—Chris McGinnis, Project Manager, LF Driscoll
The design team was also challenged to incorporate other research-oriented elements, including a new vivarium on the top floor that would be equipped with an independent ventilation system. To encourage important collaboration, open lab spaces were arranged to facilitate the use of various departments.
To encourage scientists to mingle with colleagues working on different levels of the facility, Perkins&Will’s design plan calls for a stairway to serve as “a place of exchange, a place where they can debate.” [and] ideas can be shared in passing”.
Horton says that while the design details of the overbuild sought to enhance those of the existing construction phase, the design team had to be sensitive to perceptions of equity between the two phases, as well as access to the existing building practically without land and to the adjacent parking lot.
“Obviously, we want to make a better building, but also find a ‘sweet spot’ to create improvements by keeping the characteristics of the two phases in balance,” he explains.
Planning construction activities proved equally challenging, especially given the need to preserve uninterrupted pedestrian and vehicular access to the existing structure. McGinnis says it took a month of analysis to select a Liebherr 630 tower crane for the project because its boom could freely span the rectangular building while lifting 200-pound precast facade panels several hundred feet above the ground. .
Working in a dense urban environment made logistics difficult, especially given the need to preserve uninterrupted pedestrian and vehicular access to the existing building.
Photo courtesy of LF Driscoll
“There were very few cranes on the planet that would allow us to do these things without having to be tied to the existing building,” he says.
After obtaining permission to place the crane on a section of an adjacent street right-of-way, the project team developed an 8-foot-thick carpet base supported by 12 micropiles down to a depth of 120 feet. With little room to spare, the detailed logistics plan called for daily just-in-time deliveries of steel and other large components, which were arranged at a lot about a mile away.
Even as the overbuild floors took shape, no more than two weeks of smaller materials were allowed on site at a time. “We didn’t want the floors to be obstructed,” McGinnis explains. “Everything had to go on wheels.”
Perhaps the most important consideration in the construction phase was keeping the existing building safe and fully operational. Critical issues included the highly sensitive pharmaceutical cleanroom space on the existing 10th floor and several -80°F experimental freezers, as well as the protection of rooftop generators, air handlers, and heat recovery units. energy
A particular concern was mitigating water infiltration into the existing columns as the new construction took shape. LF Driscoll built a watertight “box” around each area with a removable cover that allowed access to the top of the columns as needed. The steel columns were fabricated with watertight inclined plates within the flanges, essentially waterproofing each unit as it was installed. Welds were inspected daily for leaks.
Due to the nine-month deadline, the team ordered steel based on a basic schematic drawing in order to get material on site in time to start the project in early 2023.
Photo courtesy of LF Driscoll
Transition strategies
LF Driscoll completed steel construction in July 2023, closely followed by slab pouring, roof construction and installation of prefab and glass exterior elements. The project reached 50 percent completion in January, marking the start of what McGinnis says is the key to all of the overbuilding: the transition of existing mechanical systems to equipment located in a new mechanical attic. He adds that the project team has invested nearly a year of planning with the building’s facilities managers to develop and coordinate a complex, step-by-step change strategy, which as of ENR’s press time Midatlantic was scheduled to take place over a weekend in mid-May. .
“We’ve identified all the equipment and everything in it: where it’s located, what it powers, where it sits electrically, what it does, what alarms it links to, what department it communicates with,” McGinnis says. “We feel like we have a pretty good plan to keep things going.”
Once the changeover is complete, the remaining mechanical equipment will be demolished and the roof will be converted into the building’s new 11th floor, with laboratory space and a conference center.
“We put together a great team that we had a lot of confidence in, without the need for a learning curve.”
—Stephen Greulich, associate vice president of capital projects, Penn Medicine
Set for completion in March 2025, construction is aiming for LEED Gold certification through a combination of locally sourced recycled content, low-VOC materials, water efficiency, a green roof and optimized energy performance. The site’s limitations proved beneficial to LF Driscoll’s recycling and waste management efforts, with the use of portable wheeled carts that a disposal contractor picks up each day for sorting.
Perkins&Will’s Sabra notes that the overbuilt lab spaces are “future-proofed” to accommodate changes in use and research equipment. While some spaces are set up for highly specialized activity, others can support a wider range of uses and research activities. The conference center can also be configured as a single space or as multiple smaller rooms of varying sizes.
“The building systems infrastructure is also flexible enough for any type of seating arrangement and A/V system,” he adds.
Greulich is pleased with how Penn Medicine’s first integrated project delivery experience has worked, but says any delivery method that encourages early subcontractor involvement will yield benefits. “Just getting them working with the design team early on, that’s the most important thing,” he says.
McGinnis agrees. He says the project could not have continued without the team’s real-time collaboration and expectation of quick responses to questions and issues. “If it’s a design problem, we don’t just hand it over to the design team to solve; we work together to solve the problem with the best solution for the customer,” he says. “The same goes for a constructability issue. Everyone understands the big picture and the importance of getting this potentially life-saving research facility up and running as soon as possible.”
