Box inside a shell: a living emblem of Pittsburgh’s transformation from steel city to robotics city.
A multi-phased adaptive reuse of a 1,300 foot-long, historic steel mill, the project is located within a larger development on a 170-acre brownfield site that is being transformed into a highly sustainable, mixed-use, high-tech innovation district. The design positions the new building as a box inside the steel structural frame of the old mill. It houses office space; areas for design, prototyping, and testing; and public areas, with tenants including Carnegie Mellon University’s Advanced Robotics Manufacturing Institute.
The project showcases a variety of sustainable measures, demonstrating Buildings A and B's achievement of LEED-NC V.4 Gold certification and their design for near net-zero energy usage.
Formerly a thriving steel mill, the Jones & Laughlin (J&L) Steel Company significantly supported the War effort and helped make Pittsburgh the world’s largest steelproducing city in the 1950s.
With the decline of the city’s steel industry over time, eventually all that remained of J&L Steel was the Mill 19 site on the Monongahela River.
When Pittsburgh’s Regional Industrial Development Corporation (RIDC) purchased the property, the developer was in a quandary over whether to demolish or somehow restore the abandoned mill.
“There was the 1,500-foot-long rusting metal structure that was an eyesore, but also an icon. So, we were confronted with the challenge of how we preserve the icon and turn it into something positive,” relates RIDC President Dr. Don Smith. Fortunately, MSR Design came up with a great idea — preserving the steel’s exoskeleton, building a large solar array across the length of the roof and constructing new infrastructure for robotics, life science and AI companies.
“We briefly considered fully occupying the interstitial space between building and structure, but felt we needed to preserve the longitudinal views down the entire length,” relates Jeryl Aman, AIA, director of operations, MSR Design, Minneapolis.
So in lieu of recladding and building out the full volume of the old mill, three new connected buildings were erected inside the existing superstructure and the sloped roof was converted into a massive 110,000 square-foot solar array producing more than two million kilowatt hours (kWh) per year.
The team optimized the depth of the floor plate to be within 75 feet for enhanced daylight autonomy, to capture better air conditioning efficiencies and create a separation between the heritage shell structure and new buildings.
In order to create a comfortable, daylit space, much thought went into the selection of the glass. Based upon energy modeling performance data and a requirement to meet Cradle to Cradle® sustainability criteria, the architects went with Solarban® glass from Vitro Architectural Glass.
The 2023 AIA Committee on the Environment (COTE®) Top Ten Award Winner and LEED®-NC Gold-certified project is enclosed with Solarban® 60 glass windows and Solarban® 70 glass skylights.
MSR Design curated the varying sizes and shapes of the windows to create a rhythm of different scales that references the existing 25-foot structural bay. The daylighting design also achieves the project’s goal of 65% spatial daylight autonomy.
The architects designed monumental interior vertical stairs to cantilever toward the superstructure to link occupants within the common spaces to the historic steel exterior.
“We wanted the experience of the superstructure to be connected to the workplace environment of the interior, and the rhythm of the windows provides those regular opportunities throughout,” explains Aman. In addition, “We provided more glass in certain areas where we felt a more activated ground floor might someday take hold.”
The resulting enclosure design delivers mottled light filtering down from the bifacial solar array overhead, daylighting to 88% of the regular occupied areas and exterior views of the Monongahela River, downtown Pittsburgh and growing redeveloped Hazelwood Green district.
The Solarban® 60 glass windows block 61% of the sun’s solar energy while ushering in 70% of the visible light. And with the Solarban® 70 glass skylights, 73% of the solar heat gain is kept out and 64% of the light shines through.
Balancing performance and cost, the design limited the height of the glass panes to no taller than 143 inches. This way the 144 ¼-in. lites are supported without paying an oversized glass premium and losing an inch of glass transparency through the insulating glass unit (IGU) fabrication process.
Reflecting on the project, Aman notes, “The project provides a public promenade to help bridge the community’s connection to the new development and the artifact that is the mill structure. The amount of public circulation, gathering, recreation and reflective space for a privately developed and leased office development is remarkable.”
Commenting on the unique statement this creative adaptive reuse project makes, RIDC Senior Vice President of Development Tim White comments, “The marriage between the new and the old, the industrial past and the new high-tech, super energy efficient buildings made a great statement for where the site was and where the site is going.”