Ballinger’s Chief Structural Engineer, Angela Fante, PE, SECB, LEED AP, wrote the cover story for this month’s Modern Steel Construction, published by the American Institute of Steel Construction. The article, “Centered on Innovation,” describes how Ballinger engineers brought to life the vision of design architect HWKN and architect-of-record KSS. The building’s most striking feature is the dramatic ‘faceted façade’ at the north elevation, which had an immensely complex effect on the existing building frame.
Ballinger’s work on the Pennovation Center was recognized by the Delaware Valley Association of Structural Engineers (DVASE) at its annual Excellence in Structural Engineering Awards Ceremony May 18. The project received the award for Outstanding Structural Engineering Project in the category of Buildings $10M to $30M.
The event was held at the National Museum of American Jewish History and included presentations by Andrew Blasetti of Thornton Tomasetti and John S. Gattuso of Liberty Property Trust.
The Pennovation Center is a 62,000 SF incubator space developed by the University of Pennsylvania to foster start-ups. Ballinger engineers worked hand-in-hand with design architect HWKN and architect-of-record KSS to transform a former DuPont paint testing facility.
The design called for a glass addition “bursting” through the north elevation of the existing building. To make the design a reality Ballinger developed a highly complex framing system, with the requirement that the same thickness of existing horizontal banding created by the perimeter concrete-encased steel floor beams be carried northward into the “bursting” north addition. No beams deeper than 10″ depth were permitted to structure the entire north addition, which was to appear to cantilever 32′ at its longest point.
The resulting building is now the centerpiece of Pennovation Works, Penn’s innovation district.
The 62,000 SF Pennovation Center is an incubator space developed by the University of Pennsylvania to foster tech start-ups. Ballinger engineers worked hand-in-hand with design architect HWKN and architect-of-record KSS Architects to transform a former DuPont paint testing facility into a flexible laboratory and co-working office space. Building operations and tenant occupancy started in Fall 2016 with positive reviews from the design and engineering community and the building’s occupants.
We caught up with Ballinger’s Chief Structural Engineer, Angela Fante, PE, SECB, LEED AP.
One of the building’s most striking features is the dramatic faceted glass outcrop. Can you tell us about what went in to engineering that?
ANGELA FANTE: Through collaboration with the architect and University, we were able to meet an incredibly complex structural challenge with an elegant solution. The addition of the north elevation ‘faceted façade’ had an immensely complex effect on the existing building frame.
It is not structured with cantilevers, a misnomer many are giving the north extension’s structure.
If not a cantilever, what is it?
AF: Because the architectural design required maintaining the same horizontal banding depth across the existing to new addition interface, there wasn’t enough depth to accommodate the structure needed to cantilever the addition. Instead, we broke the north elevation into seven individual existing column frame elevations. From there, we designed new diagonal ‘column props’ and horizontal floor strut/tie beams, which impose either a horizontal tension or compression on the existing frame, at different levels throughout the geometry of the façade.
The effect on the frame was a series of ‘pushes and pulls’ on the existing building structure, none of which it was originally designed for when it was constructed in 1954. (In that era, engineers barely considered wind and earthquake loading).
How are those “pushes and pulls” supported by the existing building frame?
AF: Although the appearance of the geometry of the addition looks complex, the interface between the new and existing building boils down to 28 unique connection points (seven existing grid lines x four floor levels), each custom-detailed to develop and complete the load path from the new to the existing frame. Once the tension or compression at each of the 28 nodes transfers to the existing north column line, the ‘dots’ of the load path are connected back through the structure down to the foundation. New horizontal bracing in the plane of the floors was inserted within the existing building where required to transfer the horizontal force through the respective floor levels and then into the three vertical braced frame lines. The vertical braced frames are strategically hidden within the exterior walls or exposed to view in the co-working areas, as part of the raw, industrial aesthetic.
At the base of the braced frames, the accumulated collection of these load terminates in two-foot thick x 22’-long x full basement story height walls, ballasting the new structure against uplift and preventing the structure from lifting out of the ground.
It was like designing for the weight of 50 elephants pulling on the north face of the building.
Pennovation Center, a groundbreaking incubator space developed by the University of Pennsylvania, was certified LEED Gold by the United States Green Building Council (USGBC). Ballinger served as structural and MEP engineer of record for the project. Working hand-in-hand with design architect HWKN and architect-of-record KSS, Ballinger engineers helped transform a former DuPoint paint testing facility into the centerpiece of Pennovation Works, Penn’s innovation district.
The design of the energy systems is high performance, but with a start-up developer’s sensibility. A rooftop Dedicated Outdoor Air System (DOAS) unit with dual energy recovery wheels delivers dehumidified neutral air (63 degrees Fahrenheit) for ventilation of wet lab, dry lab and office work space without requiring any reheat. Cooling is provided via Variable Refrigerant Flow (VRF) units in each space, and heating is via perimeter radiation powered by a prefabricated condensing boiler plant on the roof. According to Ballinger Principal Jonathan Friedan, PE, LEED AP, “The system minimizes pre-investment – VRF units can be added as needed. It is also extremely flexible and able to accommodate a wide range of space uses without costly system modification or additions.” Sustainability and flexibility align with the project goal: to create an atmosphere for collaboration and creativity, with a “cool factor” to attract innovators from diverse disciplines.
The exhibition “Transformation By Design” is currently on display at Philadelphia’s Center for Architecture and Design. Organized around “Penn Connects,” the University of Pennsylvania campus master plan, the exhibition features selected projects form the past ten years. The program description reads: “With each project, Penn has sought to engage the highest caliber of architectural, landscape architectural, and engineering consultants, extending a tradition that combines continuous excellence in design and stewardship.”
Among the projects are the Annenberg Public Policy Center, a collaboration between Ballinger and Maki and Associates, and Pennovation Center, for which Ballinger provided structural and MEP engineering. The exhibition is on display through November 17. Principal Keith Mock spoke to the Philadelphia Business Journal about Penn Connects. Read the article here.