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4th & Callowhill


For the 4th and Callowhill project site, the client approached CBP Architects to understand how to maximize the value of land he owned. Located in a former industrial area between Philadelphia’s Old City and Northern Liberties neighborhoods, the property and its environs weren’t zoned for residential use, both keeping the area a chasm between vibrant neighborhoods and limiting development potential. CBP Architects worked with the client, the Northern Liberties Neighbors Association, and the City of Philadelphia Planning Commission and Water Department to develop a zoning overlay that encourages mixed-use development, including housing. The overlay was designed to encourage height through bonuses for public benefits such as stormwater management, open space, through-block connections, and mixed-income housing. Approved in 2016, the East Callowhill Zoning Overlay has transformed the area from an industrial desert into a walkable residential neighborhood.

As part of the zoning overlay development feasibility study, CBP Architects designed a conceptual project to demonstrate the site’s potential under the new zoning. The concept included dual 26-story towers containing 454 residential units, two retail spaces, and parking for 233 vehicles. A public park, public art, and extensive landscaping activate pathways previously cutoff by blocks of industrial development. By incorporating public amenities and sustainable design features, the project could benefit from increased height and density. Aesthetically, the towers’ contemporary appearance nods to the area’s industrial history via metal panel cladding, glass balconies, and warm wood accents. The combination of the zoning overlay and development concept helped the client gain a better return on his real estate sale, while the overlay has spurred new mixed-use, stormwater-friendly development in the neighborhood.

  • Project Category

    Feasibility Studies

  • Client

    Seymore Rubin Associates

  • Location

    Philadelphia, PA

  • Number of Units


  • Number of Stories


  • Gross Floor Area

    113,300 sf

  • Program

    Mixed-Use Residential & Commercial