PHILADELPHIA FREEDOM: Our city’s flexible grid and tiny lots give us more than we think

By Brian Phillips, FAIA

Philadelphia is the physical manifestation of Design for Democracy. As an architect engaged in its continued evolution, I believe that it is not the city’s nostalgic physical character or specimen architecture that makes it this way. Instead, it is the spatial organization — its system of streets, blocks and rowhouses. The city grid, designed to jumpstart a nation built on egalitarian Quaker values, was imbued with flexibility, allowing it to adapt to changing conditions over time. Much like the founding documents of our nation, which were intended as living articles, Philadelphia’s structure weaves a coherent and powerful whole cloth out of millions of tiny pieces, subtly reflecting the diverse backgrounds, stories and ideas of its people — past, present and future.

The original 1683 platting of the City’s grid by Thomas Holme on behalf of William Penn is consistent across a comfortable precinct spanning a compact two miles from river to river. Punctuated by four civic squares arranged around a fifth central square intended for public buildings (eventually the site of City Hall), this composition balanced the private and public interests of citizens with that of a shared government right from the start. Legible as a diagram of sociopolitical intent, this gridded fabric emerged from enlightenment rationality and freedom, and stood in contrast to the hierarchies of European urban structures.

"The large scale and original purpose of these blocks was not quite right for Philadelphia’s emerging democracy, however. Envisioned as green garden estates — an antidote to the crowded mazes of London — these four-acre square blocks turned out to be too big to harness the energy of a capital city for a nation founded on freedom, democracy and private property.

The large scale and original purpose of these blocks was not quite right for Philadelphia’s emerging democracy, however. Envisioned as green garden estates — an antidote to the crowded mazes of London — these four-acre square blocks turned out to be too big to harness the energy of a capital city for a nation founded on freedom, democracy and private property. In order to make space for innovation in land ownership, politics and entrepreneurship, the original oversized properties along the Delaware River were quickly subdivided and sold off into much smaller pieces, creating a powerful economic petri dish. The rest of the grid followed suit, and by 1750, Philadelphia was the second-most populous English-speaking city in the world.

The Philadelphia grid was expanded in waves over the next 100 years, with its large street blocks subdivided intentionally into tiny parcels, typically between 12 and 16 feet wide. This scale invited housing development in the form of the attached rowhouse to flourish, defining the city’s residential building typology, as well as its predominant visual language and approach to community formation. With the smallest average lot size of any city in America, Philadelphia’s urban fabric fueled homeownership at such a rate that the city’s humble but radical pavilion for the 1893 Chicago Exposition was called the Working Man’s House. A replica reconstruction of a typical brick rowhouse on the fairgrounds was a wildly popular curiosity for visitors.

While rowhouses are naturally constrained in dimension and access to light, each home has a small garden out back, a stoop or a porch facing the street, and a roof open to the sky. As a building type, they are inherently energy efficient by way of two attached walls that protect each other from surface contact with cold air. Hearing your neighbors through those walls, the intimacy between living room and sidewalk, and literal and figurative interdependence across “party walls” linking adjacent homes creates a relentless connectedness between neighbors that adds to the sense of community.

As rowhouses line up into sticks and mirror across streets to form blocks, Philadelphia’s recipe for neighborhood building emerges. Rowhouses and blocks work together to create the unique urban fabric that today is perhaps best witnessed by looking out over South Philadelphia from the terrace at Bok Bar on the 8th floor of an erstwhile technical school at 9th and Mifflin Streets. From afar, the grid spreads out as a continuous carpet, but look closer and it’s easy to see each rowhome’s unique texture — the small adjustments made by each homeowner over time — that together cohere into a topography of democracy balancing the individual and the collective. While many other contemporary cities are actively attempting to constrain the ratio of land to household by allowing additional units on lots zoned previously only for single families, Philly’s tiny lots have trained the city for more than 250 years on the ideals of living together in an urban fabric that values modesty, intimacy and community.

Beyond the experience of living here, Philadelphia’s rowhouses proved to be perfect vehicles for realizing the emerging promise of the American Dream. The small scale of the city’s lots and its block-by-block mix of industrial, commercial and residential zoning allowed many of its residents to start small businesses out of modestly scaled spaces catering to the unique needs of others in their communities. Philly’s grid encouraged average people to envision pathways to starting something new — and getting somewhere big.

Perfectly Imperfect

The progressive early politics of Pennsylvania contributed to making Philadelphia a true melting pot during the post-Revolutionary War period, with the grid continually adapted to accommodate a remarkable level of diversity in population, including free people of color, former German and French soldiers, white European settlers and Native Americans. After the Civil War, as the industrial project that gave Philadelphia its 20th century shape began to unfold, the grid became increasingly exclusionary. Accessibility to the system of homeownership was deliberately tilted against non-whites and immigrants through redlining and racism, both visible and invisible. Systematic urban depopulation after World War II, driven by the interstate highway system and the 30-year mortgage, left further challenges for American cities as industry and economic opportunity relocated to new suburbs and beyond. Philadelphia lost nearly a quarter of its two million peak population, leaving vacancy and neglect throughout the grid.

I arrived in Philadelphia in 1994 to attend graduate school at the University of Pennsylvania. The city I remember from that time still showed fresh scars from the post-industrial era, and it required patience and care in getting to know its story. Upon receiving their diplomas, my peers were quick to move on to New York City or London or almost any other place. Philly’s big brand was always history and sports, but in the ’90s, its image was characterized by the crack cocaine epidemic, gun violence, poverty and rampant vacancy. Even through that fog you could see the vitality of the place — West Philly basement house shows, bars full of artists and attitudes, a killer film series at I-House and curious yet welcoming neighbors who didn’t seem to know there were sprawling suburbs out there.

It was this platform that gave me the space (literally and figuratively) to start something from scratch. Had I left for a more “obvious” city, like some of my peers, I probably couldn’t have managed to get ISA off the ground. While the early aughts were a unique moment of economic accessibility, Philly is still special in its ability to offer multiple entry points to people from all kinds of backgrounds. The city has emerged as a leading collector of millennial and Gen Z creatives from all over America, as well as immigrants from all over the world. Its East Coast affordability within a few hours of NYC, D.C. and Boston has made it once again a melting pot of innovation. Today, Philly’s communities aren’t built on the heavy industry or technology jobs of the past (though we have some) but rather through food entrepreneurs, creative makers, government workers, teachers, nurses, artists and all of the people who make our city run day in and day out.

Despite the inequities and traumas played out across Philadelphia and other American cities, the underlying chassis of its street grid and rowhouse blocks continues to shape the people, relationships, creativity and experiences of its citizens and visitors. This city is rich with conditions that are very difficult to design for but are exactly the things that urbanists hope for. I believe Philadelphia’s recent (modest) population growth and outsized reputation for livability and community spirit is, at least in part, attributable to its grid’s built-in organization — it settles all the disparate elements of urban life into a certain comforting and energizing connectedness. I don’t think we can overestimate the crucial role of rowhouses and our tiny lot fabric in facilitating these trends.

In a city where development is substantially by-right under the zoning code — in other words, most development does not require variances or extensive public review — we all have extra shared responsibility for directing change in a productive manner. Just because you can doesn’t necessarily mean you should. Several years ago, ISA undertook a project called Rowhouse Workshop. The goal was to celebrate the physical form and social histories of rowhouse blocks. The stories and experiences collected from that project were deeply impactful in how we thought about our practice and its relationship to Philadelphia. One of the most compelling stories was told by a young couple who, like me, moved to Northern Liberties in the 1990s when houses were inexpensive and far fewer people were walking the sidewalks. Their house was affordable and gave them a start toward financial stability. When they mentioned to their suburban Philly grandparents where they had just bought a home, the grandparents reacted with surprise and said that 50 years earlier they had bought a house in the same part of town during a very similar step in their own lives. Philly had — for their family and many others like them —provided economically accessible housing across multiple generational cycles.

Be More Like Philly

Philadelphia’s urban fabric of small parts acts almost like a living fossil, wrapping the present in layers of past victories and failures of urban planning initiatives, economic cycles and sociopolitical traumas. Even though Philadelphians rightly lament the loss of old buildings as new development adds fresh layers of expansion to the grid, the rowhouse fabric is persistent, requiring its disparate pieces to continue commingling. While parts of the city that have seen vast new development can look cacophonous and unsettling in the collision of materials and forms, I hold to the idea that this mosaic is what democracy looks like. Rowhouse blocks are resilient in their ability to absorb differences, and the freedom of expression and tolerance for imperfection within that structure is ultimately a virtue.

For a city that is known for owning its underdog status, these observations are good reasons to keep our collective chins up. Philadelphia should be a leading light for democratic policy and action, continuing its role in creating an affordable haven of housing, creativity and entrepreneurship. In hard times, I worry that we don’t fully understand the assets we have and the work it will take to preserve them with the collective goal of making our city strong for the future. Philadelphia has many familiar challenges, like providing quality education, safe and clean neighborhoods, functional transportation infrastructure and well-maintained spaces for recreation. Sometimes I think that if we more deeply understood our inherited treasures from the past, we might have a more urgent drive to care for its continued well-being.

Many of us are approaching the celebration of this year’s 250th anniversary of the American experiment with mixed emotions. As we debate just how threatened our democracy is at the moment — and where it may or may not go in the near future — I feel comforted by my block, my neighborhood and my city. On a daily basis, I engage face-to-face with many of my fellow citizens along sidewalks, on SEPTA, in coffee shops and parks, and at farmers’ markets and street festivals. We share stories, partake in rituals and productively disagree — but, you know how it is…

If you’re from here…you good. And if you’re not…make sure you act like us. This city of rowhouses is a beautiful bubble to be in.

BRIAN PHILLIPS, FAIA, is founding principal of ISA and serves as creative director across all aspects of the firm’s work. He is a lecturer at the Stuart Weitzman School of Design and has taught visiting studios at the University of Miami and Parsons the New School for Design.