Louisville Police Department

Crime Prevention Through Environmental Design

Crime Prevention Through Environmental Design (CPTED) is based on the premise that elements of our physical environments can influence our emotions, cognitive function, and our social behaviors.  The proper design and effective use of the built environment can lead to the reduction in the fear and occurrence of crime and an improvement in the quality of life.

Crime Prevention is defined as strategies and actions that attempt to reduce the risk of crimes from occurring, and their potential harmful effects on individuals and society, including the fear of crime, by intervening to influence their causes.  CPTED uses these tenets as a lens to assess the physical environment and positively influence human behavior.  Design professionals have historically integrated into their work planned resistance to natural threats such as fire, earthquakes, floods, and other weather related disasters.  Crime is a man-made hazard that should also be mitigated through properly designed physical environments.  CPTED can be applied to both existing and new environments.  CPTED can be applied without interfering with the normal use of the space. It is easy to apply and can be economical to implement.

 CPTED strategies offer guidelines that property owners or managers may apply to reduce the fear and incidence of crime and improve the quality of life. There are four interrelating CPTED strategies. They include Natural Surveillance, Access Control, Territorial Reinforcement and Maintenance.

NATURAL SURVEILLANCE

Natural surveillance is based on the premise that a person inclined to engage in unwanted behaviors will be less likely to act on their desire if they can be seen.

Natural surveillance is commonly associated with the establishment of clear sightlines. The pursuit of clear sightlines must take into consideration the ability to capitalize on or generate witness potential.  Natural surveillance includes techniques such as the placement of physical features, activities, and people to maximize visibility.

Successful natural surveillance applications include:

- Orienting driveways and paths towards natural forms of surveillance such as building entrances and windows

- Increasing visual permeability of vulnerable areas such as building entrances, stairwells, playgrounds etc. through the strategic use of windows, fencing material , landscaping etc.,

- Trimming back overgrown landscaping,

- Strategically lighting pathways and other potentially problematic areas where opportunities for natural surveillance exist

- Orienting indoor activity areas to allow for visibility to the outdoors

NATURAL ACCESS CONTROL

Natural access control is a design concept that is directed at decreasing crime opportunity.  It is based on the premise that a person who is confronted with a clearly defined or strategically developed boundary, will typically show it some deference by respecting the way it guides and influences their movement as they transition from public through private space. 

	Natural access control incorporates the proper use and design of sidewalks, paving material, lighting, landscaping, fencing, art, and other design elements to guide or allow access to a site.

Successful natural access control applications include:

- Clear border definition wall providing clear border definition of controlled space

- Limiting uncontrolled and/or unobserved access onto properties, buildings and private space

- Adding dense or thorny landscaping as a natural barrier to reinforce fences and discourage unwanted entry

-Using space to provide natural barriers to conflicting activities.

TERRITORIAL REINFORCEMENT

Territorial reinforcement establishes a physical design that creates or extends an outline of property ownership. This concept includes features that define property lines and distinguish between private and public spaces using landscape plantings, pavement designs, gateway treatments, appropriate signage and “open” fences.

Territorial reinforcement establishes a physical design that creates or extends an outline of property ownership. This concept includes features that define property lines and distinguish between private and public spaces using landscape plantings, pavement designs, gateway treatments, appropriate signage and “open” fences.

Successful territorial reinforcement applications include:

- Territorial boundary creating clearly marked transitional zones as persons move from public to semi-public and private space using paving patterns, symbolic barriers or markers, signs and other visual cues

- Providing amenities in communal areas that encourages activity and use

- Avoiding the creation of no-man’s land by ensuring that all space is assigned a clear, and preferably, active purpose

- Developing visitor guides to receive people

MAINTENANCE

Lastly, care and maintenance enable continued use of a space for its intended purpose. Deterioration and blight indicate less concern and control by the intended users of a site and indicate a greater tolerance of disorder. Proper maintenance prevents reduced visibility due to plant overgrowth and obstructed, or inoperative, lighting, while serving as an additional expression of territoriality and ownership. Inappropriate maintenance, such as over pruning shrubs, can prevent landscape elements from achieving desired CPTED effects. The understanding of design intent by those conducting maintenance is especially important for CPTED to be effective.

CPTED Principal Implementation Examples

- Lock all windows and doors when not in your physical sight

- Ensure all windows and doors have unobstructed lines of sight

- Eliminate concealment/hiding spaces

- Trim ground vegetation to 2’ and under and all tree canopies to 6’ and higher

- Clearly define property lines and private spaces

- Use wayfinding/signage to inform visitors of the property of information needed

- Repair any damage to the property quickly to show a strong sense of ownership

- Install 2.5”-3” screws in striker plates of exterior doors

- Install proper lighting – criminals do not like to be seen.

- Lock up all valuables

- Never leave valuables visible in a parked vehicle

- Never leave a vehicle unlocked while unattended