Building Repairs May Lower Crime Rates

A man walks past an abandoned home in the impoverished Mantua section Philadelphia on Saturday, May 31, 2014. In a city where about 600 houses are torn down each year and 25,000 others sit vacant the issue of urban blight and abandoned homes is a real issue that affects health, crime and city pride. Jessica Kourkouni/AP

There's no denying that the environment can help determine human behavior. Previous studies have shown that people are more likely to commit crimes in neighborhoods that give off the impression that no one cares. And a new study published July 8 in the journal PLOS One shows that even small improvements to the urban built environment could actually reduce the rates of criminal activity on a block.

In 2010, Philadelphia identified approximately 25,000 vacant buildings within city limits. A year later, city officials enacted the Doors and Windows Ordinance. The law requires building owners to have working windows and doors if the unused and abandoned property is located on a block where more than 80 percent of the buildings are actually occupied. Buildings are only exempt from the ordinance if owners have applied for a permit to conduct renovations beyond replacing both windows and doors.

For the study, the researchers compared the crime rates on blocks improved through this ordinance with crime rates in randomly selected buildings in areas where the policy wasn't enforced. The researchers found areas with buildings that had working windows and doors had significantly fewer incidents of crime on record over a two-year period. In areas where the ordinance was enforced, there were an average of eight fewer assaults, 10 fewer occurrences of gun violence and five fewer cases of petty crime.

"Abandoned, boarded-up buildings are one aspect of neighborhood decay that may contribute to crime and therefore serve as a potential intervention for crime reduction. Several prior studies have found associations between vacant buildings and increases in crime and neighborhood violence," the researchers write in their study. "Our study shows that remediating abandoned buildings reduces total crimes and many forms of violence and nuisance crimes."

Other studies have looked at the impact of built environment on crime rates, but the researchers say this is the first study to examine how improvements could reduce rates of criminal activity.

The researchers say that their study does have limitations, since the ordinance only applies to buildings on blocks that are 80 percent occupied, and the impact for reducing crime rates might be less significant in neighborhoods that are inhabited by fewer people.

Regardless, their findings back up the "broken-window theory" that proposes broken windows and other building disarray gives the impression that a property has been abandoned, and therefore people assume they won't be caught if they commit crimes on that property or nearby. On the flip side, neighborhoods that are well maintained and safe tend to be inhabited by people who care about the physical environment, which extends to keeping the area crime-free.

Other studies have tested out the theory and found even individuals who say they wouldn't commit a crime are more likely to do so in neighborhoods that give off the impression that no one cares. Other studies find transforming abandoned lots into community gardens or green spaces reduced neighborhood gun violence.