Industrial Past Meets Sustainable Future
Once a home for machines, the 19th Century Roundhouse at Hazelwood Green welcomes 21st Century innovators and entrepreneurs.

Part of the shuttered, 178-acre J & L Steel Mill, the 10-bay Roundhouse originally serviced and turned train engines, redirecting the materials they carried to different stops in the production process. Now, as a technology accelerator and co-working space for OneValley, the roundhouse not only speeds the delivery of groundbreaking innovations, but it’s also on track for LEED Gold Certification.

Preserving this important piece of Pittsburgh’s past, the design uses a light touch to celebrate the existing structure while adapting it to a human scale. Partially built into a hillside, the Roundhouse was a cavernous volume, darkened by decades of industrial use and abandonment, but the removal of a century of soot from the brick walls and underside of the heavy timber roof deck warms the interior. Custom-finishes and furniture from a local network of craftspeople (Monmade)—light fixtures, the kitchen island, the reception desk, tiles, exterior benches, and bike racks—complement the historic structure’s rich material palette.

The insertion of a partial concrete structured second floor provides more office area and a featured, glass-walled event space while also scaling the space down for the comfort of its human inhabitants. The removal of unnecessary walls and the replacement of its giant, rolling garage doors with windows enables occupants to appreciate the volume of this light-filled space.

The giant windows where the garage doors once were also open views to outside, where a new public space uses native plants and public art to integrate the site’s industrial remains—its turntable, the steel frame of an old shed—into the landscape of the Monongahela River. Fitted out with movable, mounted benches, the turntable itself has become an inviting and playful place for OneValley’s tech entrepreneurs and members of the surrounding community to relax.

Connected to the surrounding neighborhood by bus routes and bike trails, the site of the Roundhouse features custom made, locally-crafted bike racks to encourage local visitors and support healthy, sustainable behaviors.