For most U.S. cities and towns, its older buildings reflect not just historic architectural styles, but a shared story of how each community came to be—its residents and workers, the products that enabled it to grow, the springing up of neighborhoods around its farms, factories, or universities.

As the decades go by, those products and services change. The needs of the community evolve. Then, we must make decisions about how to give new life to old sites. In two such cities—Pittsburgh, Pennsylvania, and Chicago, Illinois—recent building projects reflect their teams’ vision for a sustainable and prosperous future that connects with the past.

Both are certified under the LEED for Building Design and Construction (BD+C) rating system through the Core and Shell adaptation, and both are winners of multiple design awards. How did their respective teams blend up-to-date green building practices with historic character?

Mill 19 | Pittsburgh

The first of the Jones & Laughlin Steel Corporation (J&L Steel) plants was built in 1883 along the banks of the Monongahela River. For over a century, the company’s mill buildings produced steel in demand for infrastructure across the U.S. and employed as many as 12,000 workers at the Pittsburgh site. Now, 140 years after the industrial site broke ground, Mill 19 has a new life as a LEED Gold workspace housing a range of research and development tenants—providing a 21st century opportunity for the local workforce.

“The adaptive reuse of Mill 19 and the larger brownfield redevelopment of Hazelwood Green was envisioned as a living emblem of Pittsburgh’s transformation from its industrial steel-making past to a future of sustainable advanced manufacturing,” says Chris Wingate, architect and an associate with MSR Design.

The design firm began working on RIDC Mill 19 after winning a design competition for the project in 2015. Between 1998 and 2002, the site had lain fallow after J&L Steel’s closure, but redevelopment began when four Pittsburgh foundations joined forces under the name Almono LP to purchase the mill. After 20 years of brownfield remediation, planning, engagement with the public and, finally, design and construction, Mill 19 became the first completed building of the redevelopment plan.

A long mill building in a large field next to the river, with a city skyline in the background. — The LEED Gold Mill 19 is located on a former steel plant site along the banks of the Monongahela River. Photo credit: Gaffer Photography.

A technological future that nods to the past

The historic steel mill structure, which is 1,360 feet long, was incorporated into a new 260,000-square-foot commercial space for nurturing the growing R&D community in Pittsburgh.

The project’s developer, the Regional Industrial Development Corporation of Southwestern Pennsylvania (RIDC), has supported the region as it has transitioned from a steel focus to technology-based companies, says John Buechli, RIDC’s senior construction manager.

Prior to Mill 19, RIDC was no stranger to industrial redevelopment projects. The firm had developed another LEED project in Pittsburgh, the Lawrenceville Technology Center, or Tech Forge, a 172,000-square-foot facility housing robotics companies in proximity to Carnegie Mellon University’s National Robotics Engineering Center. The Tech Forge is located on another industrial site formerly used by Heppenstall Steel. One of RIDC’s goals is to have a significant impact on the community in which it is based, and the company estimates it has supported over 8,000 jobs through its Pittsburgh projects.

The tenants of Mill 19 were selected through existing relationships that RIDC had cultivated over the years as a nonprofit economic development organization. The current roster includes Carnegie Mellon University’s Advanced Robotics Manufacturing Institute and its Manufacturing Futures Institute, workforce retraining consultancy Catalyst Connection, autonomous vehicle R&D company Motional, and building facade and window systems manufacturer YKK AP. RIDC also has an office in Mill 19.

In addition to helping evolve the economic focus of the area toward advanced manufacturing, RIDC and its tenants are committed to job creation and workforce training. “From the inception of Mill 19, RIDC has partnered with local foundations, community groups and institutions to arrive at the most beneficial solutions for all the stakeholders involved,” says Wingate.

A manufacturing floor and an open office space. — The tenants of the space include high-tech manufacturing and R&D. Photo credit: Gaffer Photography.

Pittsburgh cleans up well

Certified LEED Gold in October 2023, Mill 19 has sustainable features that include a 2 MW rooftop solar array, a rainwater recycling system and a high-performance, thermally efficient building envelope. Extensive windows bring natural light into the workday of tenants’ staff and offer inspiring views of the outdoors.

RIDC shares that two-thirds of the complex’s total electricity usage is offset by energy generated on-site. Stormwater goes through a rainwater garden to central infiltration basins, and rainwater captured on the roof is reused in the cooling tower and for flushing in the restrooms.

At the time planning commenced, though, this airy building was a neglected hulk on a site representing the city’s largest remaining brownfield redevelopment. According to Jeryl Aman, project manager and director of operations for MSR Design, the 14 years of remediation efforts began with monitoring wells, soil tests and clean-up plans that took place in accordance with Pennsylvania’s Land Recycling and Environmental Remediation Standards Act. The last steel company with ownership rights to the site demolished most of the existing structures before selling the site.

“RIDC identified Mill 19 as the remaining building that could be adaptively reused,” says Aman, though salvaged materials for the razed structures were sold and repurposed to reduce waste. In addition, specific elements of Mill 19 were reused in its Core and Shell design.

“For years, residents in Hazelwood have watched other neighborhoods benefit from Pittsburgh’s resurgence,” says Aman. “Now, positive change has arrived as their steel mill is being transformed into a site for technological research, commercial use, public amenities and housing."

The building's design incorporates the former mill structure. Photo credit: Gaffer Photography.

The building's design incorporates the former mill structure. Photo credit: Gaffer Photography.

The beauty of the structure’s positive and negative space adds to its success. The original steel beams, resplendent in their patina of time, soar above the new manufacturing spaces. A full-height, full-length corridor of open space, what Wingate calls “the experiential heart” of the site, connects the new buildings and the historic frame. Visitors, passersby and Mill 19 staff alike can enjoy walkways, balconies and exposed stairways for diverse views of the structure and landscape.

Salvaged concrete block and steel were used in the landscape of rain gardens, native plants and elevated pathways. Minneapolis-based landscape architect TEN x TEN partnered with MSR Design on the creative use of the site. These elements “delineate spaces for a range of experiences,” explains Wingate, allowing smaller spots for individuals to find quiet as well as larger areas for gatherings—be they family recreational outings or city-sponsored festivals.

“It is the interplay of a publicly accessible performative landscape, the existing historic ruins and the newly inserted architecture that makes the project unique,” Wingate says.

With this type of project, certain needs must be not only met, but exceeded. Wingate sings the praises of Atelier Ten, the environmental design consultant on the project. “[They] have a wonderful ability to give voice to sustainability through analysis and impactful visualization of aspirational sustainability targets, performance analysis of design options, and documenting predicted performance,” he says.

A group effort

“Any adaptive reuse project, particularly one as unique as Mill 19, provides additional challenges as compared to a conventional, new construction project,” shares Ben Shepherd, LEED AP BD+C, LEED Fellow and director of Atelier Ten. “A LEED Core and Shell approach was specifically chosen for Mill 19 given the system’s greater emphasis on the owner elements of the design, as RIDC was seeking a high level of integrated and high-performance sustainability strategies from the project’s inception, and while potential building tenants were still being sought.”

Shepherd says the project team used a master site approach for its certification goals. It worked well for the sizable project’s phased plan and the regional market conditions for seeking potential tenants. “The LEED master site approach significantly streamlined LEED documentation efforts,” he says. “Additionally, a LEED for Neighborhood Development certification, which happened in parallel with the project, helped in achieving the LEED Location and Transportation credits in the final phase.”

An industrial-style building at twilight with grassy area in the foreground. — The LEED master site approach was used to streamline documentation for the project. Photo credit: Gaffer Photography.

All told, 10 different financing partners contributed to the project’s completion. Key to the cleanup’s success were these partnerships among foundations, public entities and private organizations, says Aman. These included four financing entities tied to sustainability, as well as traditional lenders like PNC Bank and local economic engines like the Pennsylvania Industrial Development Authority. The Richard King Mellon Foundation funded the solar array.

Buechli shares that the green financing partners were all affiliated with the federal New Markets Tax Credit, which helps economically distressed communities attract private capital. These financing groups required the project to share detailed reports on its sustainability outcomes, answering dozens of specific questions about the remediation, LEED standards, renewable energy, water savings, transit and more.

There is much for the team behind Mill 19 to be proud of. The patient efforts of all stakeholders over many years have led to a new life for the site that embraces both Pittsburgh’s past and its future. Architectural critic Charles Rosenblum wrote in the Pittsburgh Quarterly that “[Mill 19] is all Pittsburgh. Where else can you find so compelling an architectural embodiment of high-tech resurgence and ecological landscape within the mammoth rusty ruins? And what combination better unites the historical and forward-looking currents of our identity?”

Wingate reflects on what it took to make this project manifest—“years of collaborative dedication”—and he feels that Mill 19 “centered the importance of celebrating the site’s history, supporting vibrant public use and integrating aspirational sustainable design directly into the project’s fabric from its inception.”

Children play in the grassy area in front of a building. — The mill site also functions as a space for neighborhood events and for families to recreate. Photo credit: Gaffer Photography.

Community organization Hazelwood Local works with public and private partners to offer events for the neighborhood, such as art shows, outdoor movie nights and yoga under the stars. This fall, Hazelwood Local collaborated with the August Wilson African American Cultural Center to mount “S.T.E.A.M. on the Green,” a family-friendly day of hands-on science and arts activities, including a booth for kids to try their hand at building their own robots.

“We are proud that Mill 19’s positive impacts are grounded locally while being shared nationally,” says Wingate. A technological future doesn’t just mean AI or digital data; it involves an evolving definition of the manufacturing that has long been a part of the U.S. economy.

In fact, President Joe Biden has visited Mill 19 more than once to emphasize the role of Pittsburgh in this change. After becoming his party’s nominee in August 2020, he traveled to the site for his first major campaign stop.

In January 2022, he returned, remarking, “Right here in Pittsburgh, the future is being built on the foundation of this city’s storied past…Mill 19 used to roll out 10-inch steel bars. Today, it rolls out the latest innovations in advanced manufacturing, robotics, 3D printing and artificial intelligence. It’s simply rolling out the future.”

Fulton Market | Chicago

About two miles straight west of Chicago’s Navy Pier is the thriving Fulton Market District, a pedestrian hub of restaurants, shops and live music venues. Through the late 19th and early 20th centuries, this market was a center for commerce of a different kind—first, hay supplies, then meatpacking and produce. Over time, the industrial area began to empty out as its warehouses moved out to the suburbs, and the artists and cafes moved in.

Beginning in 2008, the investment of Google and McDonald’s into Fulton Market spaces accelerated its growth, and it is now a city “innovation district,” a tax designation that aims to invite new growth while preserving existing buildings and businesses.

800 West Fulton Market, a mixed-use office building standing at the gateway of this historic district, is one outgrowth of this reinvestment. The striking LEED Platinum, WELL Gold building encompasses 19 stories of space designed to offer the best occupant experience possible in terms of health and wellness, while also meeting high sustainability standards and serving as an integral part of the market district’s special ambience.

A pedestrian restaurant area in a historic district, with an office building in the background designed to fit into the landscape. — The LEED Platinum 800 West Fulton Market fits into the design of a historic district. Photo credit: Dave Burk © SOM.

A pandemic-era success story

When Chicago-based architectural and engineering firm Skidmore, Owings & Merrill (SOM) began working on the design for 800 Fulton Market, it was 2018, and no one could have anticipated the COVID-19 pandemic that lay just ahead. Construction on the building was already under way by the time pandemic response measures were implemented in the United States.

This time of uncertainty didn’t affect the Fulton Market project as much some others. “Our client, Thor Equities, asked the design team to consider whether the building would need to adapt to what was expected to be a very different workplace during and after the pandemic,” says Kevin Rodenkirch, LEED AP BD+C, associate principal and technical architect with SOM.

However, since the project was targeting LEED Platinum and WELL Gold certifications from the outset, Rodenkirch says, strategies that contribute to a healthy indoor environment were already part of the design. These features included dedicated outside air systems to continually bring fresh air into the space, a series of landscaped terraces with direct outdoor access for tenants, a window-to-wall ratio designed to balance daylighting with energy efficiency, and advanced filtration systems for air and water.

“In the end, we didn’t need to modify the design, as it was already well-suited for creating a healthy workplace—and, in our view, was ready to meet the challenge,” Rodenkirch says.

The feedback from the ownership team has been very positive, he shares, and it has implied that staff find the building so pleasant that working in the office post-pandemic is a boon. “[Tenants have] noted a strong preference for working in the office, especially among companies offering hybrid work models,” says Rodenkirch. “It’s clear that these features contribute to a workspace people enjoy.”

A multi-level atrium for an office with cast concrete, a lounge area and people walking through. — The building incorporates many features that enhance occupant experience. Photo credit: Dave Burk © SOM.

Features for a healthy workplace

In many ways, Fulton Market meets the definition of a “smart building”—one that offers technologies that improve its efficiency and enhance occupant experience. Motion and heat monitoring and IOT cloud systems maintain best practices for safe occupancy through live thermal and airflow monitoring. Passive ventilation systems can deliver a large amount of fresh air to flush out any kind of smoke or contaminant and bring fresh air inside in the event of an emergency.

In addition, the advanced systems monitoring of the building “allows people to make empowered choices that enhance their desire to be in whatever space they choose,” according to SOM’s awards application.

On the materials side, the project team found meeting LEED and WELL standards for procurement to be the biggest challenge, though 800 Fulton Market ultimately achieved 3 out of 3 credits for low-emitting materials in the Indoor Environmental Quality credit category.

Several staff members in a lounge area with tall windows. — Chemical-free materials and advanced monitoring systems contribute to healthy workspaces. Photo credit: Dave Burk © SOM.

A cozy lounge space in an office with exposed brick walls — Chemical-free materials and advanced monitoring systems contribute to healthy workspaces. Photo credit: Dave Burk © SOM.

“800 Fulton Market uses chemical-free, sustainable materials that comply with Health and Environmental Product Declarations and meet WELL standards for toxic material reduction, including the elimination of PBDE flame retardants,” says Nicholas Chan, LEED AP BD+C and sustainability engineer at SOM. Chan notes that, before beginning to work with the general contractor, SOM drew up its own, internal list of products to satisfy LEED requirements. SOM’s list emphasized materials with product declarations and low VOCs. “It was a complex process, and even after the project was nearly complete, we spent considerable time ensuring we met the required percentage thresholds of compliant materials,” says Chan.

A unique design for a unique district

SOM intended to design a building that “would feel like it had always been part of Fulton Market’s historic, industrial character, but also recognized the pressures and concerns of the new vibrant neighborhood,” according to Brian Lee, consulting design partner for SOM.

Rodenkirch describes the challenges of walking this aesthetic line in an area surrounded by both new developments and older structures. “To respect the site’s context, we focused on two primary elements: massing and materials,” he says. “We positioned the building’s core toward the northern edge, near the newer glass building, which allowed us to create a podium that aligned better with the lower brick structures around Fulton Market. For materials, the area has a mix of brick colors and black metal, so we spent considerable time selecting a brick blend that would harmonize with the neighborhood without mimicking any specific building.”

A modern office building entrance uses brick, steel and glass. — The building's design is meant to harmonize with the historic neighborhood. Dave Burk © SOM.

Rodenkirch also points to the building’s high level of craftsmanship, including hand-laid terrazzo floors in the lobby and a carefully crafted, cast-in-place concrete mezzanine. “The full-wall art installation opposite the entry adds another layer of artistry to the space,” he says.

Making access to natural, biophilic elements a priority was part of the impetus behind the striking stepped terraces, which also reduce the impact of the building’s height at street level.

In the “Windy City,” says Rodenkirch, exterior terraces are rare for office buildings, especially ones dedicated to individual tenants, but the terraces turned out to be a triple threat—an attractive design feature, a way to maximize exposure to fresh air and a bonus for the tenants lucky enough to snag a space that included one. “There was some risk early on about whether these spaces would be desirable, but they turned out to be highly sought after, and the floors with terraces were ultimately the first to lease,” Rodenkirch says.

The project team included a variety of women- and minority-owned subcontractors. Omni Ecosystems led the landscape design. “Their work on the terraces and occupiable roof spaces not only enhanced the tenant experience by providing outdoor areas to enjoy and work, but also increased the building’s rentable space without adding to the floor area ratio,” says Rodenkirch. Since the project’s completion, the firm has noticed several new designs in the area incorporating these types of outdoor spaces.

A series of diagonally designed terraces with trees and greenery. — Omni Ecosystems, a certified Women-Owned Business, led the landscape design of the terrace spaces. Photo credit: Dave Burk © SOM.

Engineering firm and LEED Proven Provider dbHMS handled the mechanical, electrical and plumbing and the energy modeling for 800 Fulton. “Their work was crucial in analyzing various design options to optimize mechanical systems, massing and the facade to reduce energy use—this was essential in helping us achieve LEED Platinum,” says Rodenkirch.

Using a variable refrigerant flow mechanical system, which Rodenkirch notes is uncommon in the area, and maintaining a window-to-wall ratio of 54% helped the project achieve its high energy performance, and with minimal carbon offsets (around $1,200 per year), it also achieved net zero emissions for the base building spaces.

The success of 800 W. Fulton Market led to a USGBC Leadership Award in 2023 for Green Building of the Year: LEED for Building Design and Construction. To Rodenkirch, the elements of wellness features, energy performance, and quality materials and design make the project not only unique, but also “a benchmark for future office buildings in Chicago.”

LEED Core and Shell projects bring sustainable character to their communities