High rates of criminal activity in cities can be costly, beyond just the obvious financial implications: more criminal activity leads to a greater need for police presence; crime can have a direct effect on property values; crime can invoke fear in residents, reducing their overall happiness and sense of safety; as well as a variety of other detrimental effects. Now imagine for just a moment that you could protect your home or business from criminal activity through relatively easy design modifications. ‘Crime Prevention Through Environmental Design’, or CPTED, is a concept originally credited to criminologist, C. Jeffery Ray, (1971) While the notion that crime and the environment were directly related had been explored prior to the work of Ray, he receives credit for coining the acronym ‘CPTED’, for formally introducing the concept and for the foundation of modern uses of the guidelines. The idea that crime could be dramatically reduced using somewhat simple concepts of urban design is the core of CPTED and despite its rather lengthy theoretical history, is still a relatively new notion in terms of implementation. As of 2014, many cities are just beginning to introduce these principles in their urban development plans. ‘CPTED’ guidelines can be used on both large and small scales, making it versatile and able to be used in a variety of applications from commercial to residential and beyond.
Although the concept of ‘designing out crime’ was originated by Ray, modern principles of CPTED are primarily based on the work of Oscar Newman, who conducted empirical studies that established a definitive connection between crime and the built environment. Newman (1996) further explored the theoretical concepts of CPTED as presented by Ray, streamlining and better defining the specific elements of design that would contribute to the creation of what he termed “defensible space”. Newman’s book Design Guidelines for Creating Defensible Space, defines defensible space as “a residential environment whose physical characteristics—building layout and site plan—function to allow inhabitants themselves to become key agents in ensuring their security.” He further explains that a housing development is only defensible if residents intend to adopt this role, because defensible space is a sociophysical phenomenon, meaning both society and physical elements are required to ensure a successful defensible space. While the history and theory behind CPTED and defensible space are somewhat complicated and complex in nature, application of the principles are based upon three relatively simple concepts: natural surveillance; natural territorial reinforcement and natural access control.
Natural surveillance uses many simple elements of design and practice, in the operation of business, to help prevent criminal activity and ultimately, protect the physical structures in a neighborhood. In the planning and development phase of construction, developers can choose to orient their building conducive to high visibility from the streets, as well as creating permeable pedestrian areas. These concepts require advanced planning but when utilized are relatively inexpensive, if not completely free. Home and business owners can increase the natural surveillance by cutting back trees and shrubs outside their properties. Leaving windows without shades to increase visibility can also effectively dissuade burglary or other crime.
Natural Territorial Reinforcement
By using buildings, fences, pavement, signs, lighting and landscape to express ownership and define public, semi-public and private space, “natural territorial reinforcement” occurs. Natural territorial enforcement can be utilized not only in the planning phase, but can also be useful in the existing built environment, as many of the attributes can be implemented after development is complete.
Natural Access Control
The third concept of CPTED, “natural access control”, relies upon clearly defining private and public spaces. Buildings can be oriented to deter criminal activity, such as theft, by strategic placement of entries. He further describes how various techniques such as high windows and “thorny” plants can serve as a building’s natural protection. Landscape elements can be planned to require low maintenance, low cost, but with highly effective defense of structures while maintaining a pleasing aesthetic.
While the primary emphasis of CPTED is to reduce the need for strong police presence in communities and to improve crime rates through urban design methods, the benefits of implementing these practices reach far beyond the crime prevention scope. In many ways CPTED promotes sustainable development practices by encouraging developers to consider natural surveillance through increased pedestrian mobility. Furthermore, with an increased degree of citizen involvement in the surveillance and safety of their community, the need for constant and strong police presence will be significantly reduced. Consequently, this reduced need for police presence will offset public safety costs for the city, while the reduction in crime will also benefit business owners and protect their interests. As a result, residents will feel safer in their community and ultimately the area will become a more desired place to live.
Feature Image: Rendering of a planned sustainable community. Image via Jennifer Gomes, Openlab Architect.