Nested within the armature of a 1,300-foot-long historic steel mill along Pittsburgh’s Monongahela River at the heart of Hazelwood Green, two new buildings sit in the shadows of trusses clad with solar panels. The 5-acre multi-phased adaptive reuse project is nested within a 170-acre brownfield site that is being transformed into a highly sustainable, high-tech innovation district. The preserved steel frame of the Mill celebrates the history of labor and a regenerative future while providing new landscapes and experiences made from post-industrial remnants. An event plaza, stormwater channel, gardens that display disturbance-adapted vegetation, and public gathering spaces define a reimagined public realm that celebrates industrial legacy.


A team of architects, engineers, landscape architects, and sustainability consultants committed to deep collaboration and a transdisciplinary approach to the design from the initial competition stage through construction oversight. From the beginning, the design for the project set out to investigate, embody, and honor the Mill’s industrial legacy across the landscape and architecture. The original Mill’s metal walls and roof were stripped away, intentionally revealing its underlaying steel superstructure. The preserved and deconstructed exoskeleton reinterprets the former volume of the Mill, honoring the ghost of what was while positioning the structure as part of the landscape.

Beneath the exoskeleton, there will be a 264,000 square foot high-tech complex separated into three new buildings positioned as an assembly line of boxes down the center of the Mill. The first two buildings in Phase A and B house office space; areas for design, prototyping, and testing; and public areas, with tenants including Carnegie Mellon University’s Advanced Robotics Manufacturing Institute. The project is a living emblem of Pittsburgh’s transformation from steel city to robotics city.

The landscape architects collaborated with the architects to help identify opportunities for deconstruction and preservation of the exoskeleton, scaling interventions in the landscape to celebrate the tectonics of the structure, while weaving together vertical circulation features and new opportunities to gather, explore, and relax amidst wild disturbance-adapted gardens.


Phase A and B highlight a range of sustainable measures to meet the goal of achieving LEED-NC v4 gold certification and near net zero energy usage. The landscape architects collaborated with the sustainability consultants to identify and integrate key sustainability strategies into the landscape, including material reuse, stormwater management facilities, and disturbance-adapted planting gardens focused on carbon sequestration and resilience over time. The inability to infiltrate stormwater above contaminated soils in the southern end of the Mill was the site’s most significant constraint and greatest opportunity. The landscape team designed a twelve-foot-wide water channel flanks the entire western façade of the Mill. The channel carries water away from the contaminated soils and visibly conveys 1.1 million gallons of rainwater through a sequence of wetland retention basins and infiltration gardens; water that cannot infiltrate collects in a below-grade cistern. The facility provides a 52% reduction in potable water use with rainwater reuse for cooling towers and building flushing.

Spontaneous plant species like sumac, black locust, willow, quaking aspen, ferns, and sedges form the backbone of an array of wild gardens. The planting design embodies the unruly and tenacious qualities of post-industrial landscapes, providing substantial ecological services that are low maintenance and low cost. The design integrates aggressive disturbance-adapted species that store carbon at a faster rate, with slow growing native species that sequester considerable amounts of carbon over time.


Through a careful process of inventorying, salvaging, editing, restraint, and innovation, the team rejected erasure and integrated new elements made from remnants of the past. Early site investigations inventoried the textures, materiality, and character of the post-industrial site and structure through rubbings and clay impressions. These site explorations captured the tactile authenticity this place, providing evidence of the power, ingenuity, and incredible technology that was forged here and forever changed the face of American industry. The rubbings and clay impressions informed joinery details, material selections and finishes across the various furniture and hardscape elements within the new landscape.

Other landscape architecture offices involved in the design of landscape: D.I.R.T. Studio
Architecture offices involved in the design: MSR Design, R3A

Project location
4501 Lytle St, Pittsburgh, PA 15207

Design year: 2015

Year Built: 2021

Photo Credit: Gaffer Photography


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