During its decade of population growth, Philadelphia’s home prices essentially tracked the rate of inflation. Unlike newer cities that have the option of relatively cheap greenfield development, the Census designates nearly all of Philadelphia’s neighborhood as urban, the densest designation. The city’s population growth has been accommodated through infill development and the renovation of old homes rather than through greenfield development.

It’s not the case that Philadelphia’s zoning regime accommodates as-of-right growth. Philadelphia developers have to deal with a complex web of outdated Euclidean zoning rules and myriad overlays. But developers have generally been able to get the variances they need to provide a supply of housing that keeps prices from rising in response to population growth. Philadelphia doesn’t have organized political opposition comparable to NIMBY activity in more expensive cities.

Residents’ reaction to calls for community involvement in the development process demonstrates the city’s anti-NIMBY tendencies. In 2012, the city implemented zoning code reforms with the stated goal of both increasing the percentage of development that’s built as-of-right and increasing community involvement in approval decisions. The new code formalizes standards for recognized community organizations and requires developers to give these groups notice for significant proposed projects. For projects of at least 25 units or 25,000 square feet, developers must undergo civic design review which requires them to meet with community organizations established near the project.