Bill would limit urban ‘McMansions’

City Councilman Mark Squilla introduced a bill on Thursday that would prohibit single-family housing in areas zoned CMX-3, which is intended to be a relatively high-density commercial mixed-use zoning classification.

The mix of uses permitted in the CMX-3 zone were intended to create dense, vibrant commercial areas. What’s happened instead, in some cases, is that developers have taken advantage of the liberal dimensional standards of the classification—looser height limits, for example—to build extra-large single-family homes. Picture the Ross Luxury Townhomes on Arch Street in Old City, with street-fronting garages.   

As Matt Ruben, the president of Northern Liberties Neighbors Association, wrote in PlanPhilly earlier this year:

The problem is that while CMX-3 allows apartment buildings with businesses and lobbies on the first floors, it does not require a commercial component. So developers can instead build single-family homes on CMX-3 property.

This loophole lets developers put residences at the street level, diluting commercial corridors. And because CMX-3 height, open-space, and parking rules are meant for apartment buildings, it lets developers build overgrown townhouses with insufficient yards, whose large size is out of proportion to the neighborhood and draws buyers or renters with more cars. It creates a perverse incentive for single-family home developers to seek out CMX-3 properties instead of properties actually zoned for single-family residential development.

Squilla’s goal is to close that loophole.

“The intent of it was to allow a residential use in a CMX-3 building, that was the intent when the code was passed,” Squilla said on Thursday. “What had happened is people were actually, in areas where we thought we would have mixed-use commercial and residential, were just building single-family homes in a CMX-3 zoned area, which wasn’t the intent.”