Philadelphia’s modernist buildings are pretty much overlooked, and we’re trying to change that,
said Suzanne Singletary, director of the Center for the Preservation of Modernism at Thomas Jefferson University.
A yearslong mapping project launched by researchers at the university now catalogs almost 700 midcentury modern structures across the city. The interactive tool aims to bring visibility to an architectural era often overshadowed by the city’s colonial and Victorian landmarks.
The database features structures like the Municipal Services Building at 1401 John F. Kennedy Blvd., Three Penn Center, and the Roundhouse, which the map designates as one of Philadelphia’s most iconic and contested modernist sites. Researchers continue walking city streets to uncover residential buildings, schools, houses of worship, libraries, and fire houses.
Midcentury modern architecture typically relies on clean, straight lines without ornamentation. Key features include expansive walls of windows, flat roofs, and interconnected interior spaces built from metal, glass, and stone.
Kevin King, a graduate student in Jefferson’s historic preservation program, described the structures as characterized by off-the-shelf materials and simple forms.
He added that while they do not jump off the street in the way high styles do, both deserve appreciation and preservation.
Paul Steinke, executive director of the Preservation Alliance for Greater Philadelphia, noted that modernism was meant to signify a departure from historical styles rooted in European precedent.
The project pairs the Center for the Preservation of Modernism with the Preservation Alliance and the Philadelphia-area chapter of Docomomo US. Organizers also drew data from the Philadelphia Architects and Buildings Project and an inventory built by the Preservation Alliance more than a decade ago.
That earlier inventory was sparked by the demolition of the Sidney Hillman Medical Center at 2116 Chestnut St., a modernist building constructed in 1950 and designed by architect Louis Magaziner. After five years of legwork, the new map went live in September, and creators plan to expand it beyond city limits.
Featured sites include major residential locations such as the Philadelphian at 2401 Pennsylvania Ave., the Hopkinson House on Washington Square, the Academy House at 1420 Locust St., and the Parkway House at 2201 Pennsylvania Ave. Landmarks like the Landmark Ritz Five movie theater and the U.S. Mint at Fifth and Arch Streets also appear.
The catalog includes works by prominent architects like Louis Kahn, Frank Weise, and Elizabeth Hirsh Fleisher, the first woman in Philadelphia to earn an architecture license. Entries span properties listed on the Philadelphia Register of Historic Places, sites with rejected nominations, unnominated structures, and buildings already demolished.
Users can search the database by architect or building name to view photographs, construction dates, and historical notes. Researchers hope the tool aids preservationists, students, and residents.
Singletary warned that without broader appreciation, these structures face the constant threat of demolition before residents recognize their value.
