Thursday, January 18, 2018

Bipolar CPTED - Inclusion or Exclusion?

Access controls with lavender - CPTED can be beautiful
by Gregory Saville

Reflecting on Tarah's excellent blog last week on the need for access control in public housing, I came across an article I wrote a few years ago that adds another dimension to the access control story. I thought I’d share…

CPTED is inclusive, but only if it is used to help residents socialize and take ownership of their common spaces. If not, the results are like the sugar-sweet candy bar; it tastes yummy and satisfies children, but if overused it leads to heart disease and, when the sugar kicks in, the kids go nuts.  

How does it work? CPTED reduces crime by dividing the public realm into semi-public and semi-private spaces. For example, architects design a landscaped courtyard in front of an apartment building entranceway so residents feel that space belongs to them. But CPTED can also exclude some groups. 

Access control fencing around hotel
Is it needed? What's the crime like outside the fence?

Developers use access control to build exclusive gated communities to keep outsiders away from wealthy, enclosed residential areas. Or the tactic called target hardening might use reinforced bullet-proof windows in bank teller areas to deter robbers. But that can also create a psychological barrier between legitimate customers and make it difficult for tellers to provide a more personal service and get to know their customers.


Sometimes CPTED can have both inclusionary and exclusionary impact. For example, back in the 1980s and 1990s, Los Angeles and Dayton, Ohio barricaded selected road entrances into high crime neighborhoods to cut drive-by shooting and drug dealing. Barricading and target hardening are the candy of CPTED - they feel good and they feel they should work. And sure enough, shootings and drug activity did decrease, at least initially. But later crime increased as criminals adapted to the barricades. Furthermore, residents complained about being more isolated, the inconvenience of the barriers, the traffic impact on nearby neighborhoods. Worse still, in Los Angeles they complained about not being invited to participate in planning.

Inclusionary public plaza in Europe - No fences required
Clearly, CPTED has a bipolar nature – inclusion vs exclusion. The devil truly is in the details! As Jacobs said in Death and Life of Great American Cities: “The first thing to understand is that the public peace …of cities is not kept primarily by the police, necessary as they are. It is kept primarily by an intricate, almost unconscious network of voluntary controls and standards among the people themselves, and enforced by the people themselves.”


Beware of these exclusionary triggers:

  • CPTED checklists that list details for design. Some details can help, for example, lighting. But not always. Lighting research is inconclusive! In some cases, increased lighting can attract unwanted activity, or make it easier for drug dealers to see oncoming police. Therefore lighting may cause more harm than good. It may be necessary to turn lights out to cut crime. A better alternative to checklists is CPTED guidelines with examples and photos of positive designs, and requirements for a proper risk assessment prior to CPTED tactics.
  • CPTED that controls access, such as fencing around property, but doesn’t provide alternatives for socialization. For example, when children walk down residential streets lined with chain link fences they learn they are outsiders in their own neighborhood. Children need inclusive, semi-public play areas near where they live to feel they belong.
  • CPTED courses that teach students design tactics but ignore, or pay minimal attention, to 2nd Generation CPTED. That is where exclusionary errors begin! 

Thursday, January 11, 2018

Shoot the girl - CPTED in public housing

Public housing, London, UK. - photo Iridiscenti Creative Commons

by Tarah Hodgkinson

A few years ago, a scorned lover walked onto a public housing project and shot his ex-girlfriend. She lived but has suffered terribly with her injuries ever since. The man did not live there, so how was he able to get onto the property and shoot his ex? Was this a fluke, spur-of-the-moment occurrence that might have been prevented?

In a journal article coming out this year, myself and some colleagues describe how we used crime mapping and analysis to examine questions about such crimes in public housing. We compared the police calls for service over a 7 year period at four nearby public housing facilities of similar size and occupancy. The housing where the shooting (and many other crimes) occurred went through a massive reconstruction during this time. This construction was intended to upgrade the living facilities and improve the overall livability and security of the location.


However, after the construction, we found not only did calls for police service start going back up, but they did so dramatically. In fact, the trend was increasing at a rate that surpassed previous levels of calls for service. This seems counter-intuitive. Why would a place that had made improvements to the image and maintenance of the property, as well as security, see an increase in calls for service when the other public housing developments didn’t?

We conducted field research that provided some context. While interviews with property managers demonstrated knowledge of security measures, particularly CPTED principles, some of these principles were not properly implemented in the redesign.

Another example of public housing with poor access controls - Vancouver, BC

For example, they constructed a large fence around the perimeter but failed to replace access control gates and security at key points. The redesign had major openings with no gates or doors to restrict outsiders from entering or exiting. While the entire site was fenced, there was no real access control in or out of the property. Unlike other locations we examined, not only did this facility not have security at the entranceways, it lacked a strong community presence. Thus, there were very little natural surveillance opportunities or proper access controls at the entry points where it mattered most.

Clearly, the lack of proper security measures in public housing, like access control and surveillance, can increase the risk of victimization. In this case, it is unsurprising that an outsider was able to walk right through the front entrance, unchallenged, and shoot his ex-girlfriend.

The implications of poorly implemented CPTED are clear, particularly for responsibility and accountability: accountability for competently implementing CPTED principles in a high-risk location, and responsibility for adequate security in public housing facilities to protect vulnerable residents.