A Philadelphia Story: Decades of Regeneration Add Up in the City of Brotherly Love

Located at the confluence of the Delaware and Schuylkill Rivers, the Philadelphia Navy Yard is now the largest LEED ND in the world. A maritime hub for more than a century, the 1,200-acre site today revels in lush green splendor nurtured by sustainable infrastructure.

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Founded in 1682 by William Penn, an English Quaker who advocated for religious freedom, the city of Philadelphia is a key cog in U.S. history and heritage. Known as the “City of Brotherly Love,” Philadelphia is home to 67 National Historic Landmarks, including Independence Hall, where both the Declaration of Independence and the Constitution of the United States were debated and adopted by the Founding Fathers.

One of the oldest cities in the United States, Philadelphia is home to many firsts, including the nation’s first library, hospital, medical school, central bank, stock exchange, business school and zoo. Amongst it all, at the confluence of the Delaware and Schuylkill rivers, the Philadelphia Navy Yard has played an important role in the city’s story.

Historical Significance

Strategically located, the site began as a commercial shipyard during the American Revolution, founded on Front Street along the Delaware River in 1776. Standing as an active military maritime hub for more than 125 years, the Philadelphia Navy Yard had been a longstanding economic powerhouse for much of Philadelphia’s history. The site employed as many as 40,000 workers operating in shifts to repair damaged ships during World War II. In 1994, the U.S. Navy ended most of its activities at the shipyard through the Base Realignment and Closure Commission and officially ended military activities in 1999 after 128 years of service.

“In the late 1990s, the U.S. government turned the Navy Yard over to the City of Philadelphia,” begins Scott Kelly, architect and sustainability consultant at Re:Vison, a design practice committed to restoring the balance between natural, built and social environments. “By 2000, the Philadelphia Industrial Development Corporation (PIDC) acquired the 1,200-acre site and began to redevelop the land. Twenty-five years later, the Navy Yard is once again an economic powerhouse for the city of Philadelphia. It’s also the largest LEED Neighborhood Development (ND) in the United States, achieving a LEED ND Gold Certification from the U.S. Green Building Council in April 2025.”

 

Kelly is a Philadelphia native, so he’s proud to have played a part in restoring glory to a site that has long been a lifeblood of South Philly. There was a time before he became involved at the Navy Yard that Kelly imagined leaving Philadelphia. Now, he’s glad he didn’t.

“In 1993, my first job in architecture was documenting historic buildings around the city, some of which were in the Navy Yard. For me, historic preservation was the entry point into sustainability and deep green consulting,” says Kelly of his design journey’s beginning. “At first, sustainability didn’t seem to be catching on around here. In 1999, I was thinking of moving to some place like Boulder, Portland or Asheville, where green thinking was more established.

“Unexpectedly, I got a call from a former client who wanted help getting their offices certified,” he explains. “Then, a local school called about an addition targeting LEED certification. Twenty-five years later, Re:Vision has contributed to hundreds of projects around Philly and across the country, spanning higher education, civic use, churches, schools, nature centers and single-family homes. We help designers and builders achieve a balance between mankind and nature. The Navy Yard is an exemplar.”

New Navy Yard

Since the early 2000s, the Navy Yard has attracted more than $1 billion in public and private investments enroute to becoming the workplace of more than 100 businesses employing thousands of people. It’s home to a wide-ranging collection of internationally recognized brands such as Urban Outfitters and Tasty Baking Company—a subsidiary of Flowers Foods and makers of Tastykake, Philly’s iconic snack. Dozens of engineering, architecture and design firms join a plethora of medical product companies, occupying a mesmerizing collection of architecture old and new. Since the site remains a reserve basin for retired Navy vessels, aircraft carrier U.S.S. John F. Kennedy and other honored ships moor at the docks. The site’s unusual assemblage of past and present, steel, brick, glass, greenspace, and massive warships presents an urban environment unlike anything else in Philadelphia.

 

“The first masterplan for the Navy Yard designed by Robert A.M. Stern Architects in 2004, and updated in 2013, connected the site to Philly’s historic road grid running off of Broad Street,” continues Kelly. “My engagement at the Navy Yard began with the plan’s first new building, One Cresent Drive, developed by Liberty Property Trust. This four-story, 75,000-square-foot multitenant building was one of the first LEED Platinum Core and Shell buildings anywhere in the world.

“Since then, I’ve been involved in more than a dozen buildings at the Navy Yard,” he adds. “Liberty Property Trust was smart not to let one architect dominate. I worked with about 10 different internationally acclaimed design practices. My job was to help each team understand the Philadelphia context and the Navy Yard’s unique sustainability challenges.”

Today, the Navy Yard is thriving. More than 150 companies occupy more than 7.5 million square feet of office, industrial, manufacturing, research and development space connected via walkable districts. Recognized by entities such as the Urban Land Institute as a model for repurposing former military and industrial sites as live/work/leisure lifestyle epicenters, the Navy Yard has now emerged as a city within a city.

“The job creation at the Navy Yard has been incredible,” says Kelly of the prosperity he looks for as an indicator of success in his work. “These buildings are all designed for low-energy, low-carbon, minimal toxicity and maximum human comfort. They perform above code. Outside, the streets are tree-lined and populated by people running, walking and bicycling. There are parks every few blocks, and people come from other parts of town just to enjoy it.”

 

 

Commitment to Sustainability

Sustainability is more than a scorecard, however. At the community level, true sustainability is a shared journey that requires dedication from many.

“When Liberty Property Trust relinquished development rights, Ensemble and Mosaic were selected as the developer of a substantial portion of the Navy Yard through a public RFP process,” shares Kelly. “As part of its planning efforts and vision for the future of the Navy Yard, the leadership of PIDC, Ensemble and Mosaic committed to applying a sustainable ethos to everything in the Navy Yard from the streets to the infrastructure.

“The LEED ND certification demonstrates that the commitment to sustainability does not end at the building,” he adds. “As more companies and people move to the Navy Yard, this certification validates that this built environment is healthy, environmentally responsible, economically beneficial and vibrant.”

To achieve the LEED ND Gold certification, Ensemble, Mosaic and Re:Vision addressed criteria established by the U.S. Green Building Council in three categories: 1) Green Infrastructure and Buildings, 2) Smart Location and Linkage, and 3) Neighborhood Pattern and Design. The first focuses on the sustainable construction and operation of infrastructure and technologies that minimize waste while using energy, water and materials more efficiently than conventional building practices.

The Navy Yard was ripe for a rethink when PIDC master planned it in 2004. Linkage points are awarded for reducing sprawl by creating a more livable, walkable community adjacent to existing developments. Located within walking distance to the home arenas for the Philadelphia Eagles, Phillies and 76ers, the Navy Yard offers Philadelphia sports lovers a home-field advantage beyond imagination. The final category of credits emphasizes the creation of compact, walkable, vibrant, mixed-use neighborhoods that improve connections to nearby communities.

As the largest LEED ND project in the United States, the Navy Yard sets a new highwater mark for eco-conscious urban design by laying a pattern and following it. Cutting energy use, enhancing air and water quality, and minimizing the carbon footprint of a 1,200-acre urban infill presents the Navy Yard as a national model for what to do with inner-urban brownfield reuse.

Commitment to Communities

Like Kelly, Elizabeth Norton spent most of her career working on projects at the Navy Yard. Associate Vice President Norton is the land development manager at Pennoni, a top consulting engineering firm founded in Philadelphia in the 1970s. She took an entry-level position with Pennoni after graduating from Penn State University with a degree in Civil Engineering and has never worked anywhere else.

“Pennoni is a multidiscipline engineering firm employing more than 1,400 people in offices across the eastern seaboard,” she notes. “The firm takes pride in our commitment to communities. We strive to improve infrastructure while contributing to a better quality of life through service, education and encouraging staff development in diverse community organizations. I’ve spent the last 25 years working on projects at the Navy Yard. It’s been thrilling to work on iconic, skyline-changing projects designed by brilliant architects.”

Norton reveals that it’s difficult to describe how much things have changed at the Navy Yard in the time she’s spent working there. Though much of what’s there now is new, there are also dozens of former Navy buildings of various typologies reclaimed as leasable space for modern life’s niceties: fitness studios, restaurants, physical therapy offices and travel agents. Pennoni’s role was to guide the physical implementation of the vision set for the Navy Yard through what’s now a life course in the evolution of site-sustainability strategies.

“Pennoni helped Liberty Property Trust as well as the Ensemble and Mosaic team develop more than eight miles of new road and design the utility infrastructure that services nearly 8 million square feet of multi-use commercial real estate,” she shares. “This was 1,200 acres within an ultra-urban setting that we considered a blank slate. Using LEED as a guide, we collaborated with utility providers, developers, the city and the design consultants for each project to bring water, gas, power, sewer and telecom to these parcels. Along the way, we developed some of the first green street infrastructure in the city of Philadelphia.”

Green Streets

The Navy Yard’s green streets plan prioritizes sustainable stormwater management and clean, low-maintenance, infrastructure such as bioswales, rain gardens and tree trenches.

“We tried to reduce the volume of impervious surfaces draining to stormwater inlets and instead use stormwater to fill rain gardens or tree trenches to recharge the groundwater table,” explains Norton. “The low-impact systems in place at the Navy Yard allow the site to use the first inch and a half of rain runoff. So about 95 percent of all stormwater at the Navy Yard helps keep green spaces green by returning runoff to nature without processing.”

Green streets are hardly the extent of it. During the last 25 years, architects and engineers tackling projects at the Navy Yard tested dozens of different sustainability strategies. What was innovative 20 years ago is now practical design.

“Aside from all the porous pavement strategies, many Navy Yard projects incorporate pavements with a low solar reflectivity index rating, meaning it doesn’t absorb as much sunlight,” continues Norton. “Strategic building placements help reduce heat zones and optimize daylight inside workspaces. There are also quite a few buildings with green roofs, which further decrease the volume of site runoff and required water treatment induced by the site.”

 

 

Getting the Gold

It’s the compounding layers of sustainability across nearly a generation of change that make the difference at the Navy Yard. The returns are more than less waste and more efficient use of energy. The LEED ND Gold certification at the Navy Yard means the entire community enjoys reduced operational costs and a walkable environment that places a priority on the health and wellness of those that work, live and visit. In 2025, businesses recognize the positive recruiting and branding impact of locating in an environmentally conscious ecosphere. With more than 150 companies now on the Navy Yard campus, the redevelopment has created an estimated 16,000 jobs so far, marking a significant contribution to the Philadelphia economy.

While Norton and Kelly celebrate the recently awarded certification, marking a milestone in their careers, the accomplishment also is a testament to just how far “green building” has come in the first quarter of the 21st century.

“The LEED ND Gold certification marks the completion of a process we started more than 20 years ago,” note Kelly. “It’s good for the site, the city and the citizens of Philadelphia. Right now, there is no residential at the Navy Yard, but with 614 apartments under construction and more than 4,000 residences planned, there will be housing for all income levels—from the lowest to the highest—and people of all ages. The Navy Yard will be home to people who want to ride their bike to work, walk to brunch on Sunday and enjoy life low-key while being easily accessible to everything the city of Philadelphia has to offer.”

 

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