Basic Crime Information
Types of Crime
Environmental Criminology
Heirarchy of Crime
Determiners

CPTED Crime Analysis

Design Principles
Design Guidelines
Design Examples
Origins of CPTED
Links

Design Principles

These are only a few of the many design principles that skilled design professionals use to reduce opportunities for crime. Many of these principles are still being developed.

The design principles noted have been developed in the Vancouver Metropolitan area and are based upon the typical building form of development and the specific crime environment. Application of these design principles should take place in conjunction with a full understanding of the local building forms and crime environment.

1.   The Jane Jacobs Test
2.   Actual Risk Approach
3.   Designing to Reduce "Fear of Crime" versus Actual Risk
4.   Encourage Watching
5.   Create a Sense of Ownership / Claiming Public Space
6.   The Street as a "Functioning Unit"
7.   Relationship of the Residential Unit to the Street
8.   Relationship of the Commercial Unit to the Street
9.   Sending the Wrong Message
10. Cut-throughs and Multi-Access Sites
11. Seamless Connection to the Street for Public Places/Parks
12. Clear and Clean Visibility
13. If You Light It, They Will Come
14. Break and Enter: Areas of Concealment Versus Privacy
15. Awareness Spaces: Removing a Potential Target
16. Alternate Routes
17. Street Closures
18. Positive Effect on Surrounding Areas
19. Infusion of Community Resources
20. Infusion of Legitimate Populations
21. Positive Effects of Management Programs
22. Neighbourhood Genesis to Crime
23. Exterior Corridors
24. Pedestrian Underpasses

1. The Jane Jacobs Test

A holistic approach which balances reduction of crime opportunities with other objectives which achieve good design and enhance the built environment.

All designs that attempt to reduce opportunity for crime should be tested to ensure that they also support and enhance the overall urban environment, both social and physical, through improved design and beautification.

 


Both of these fences reduce opportunities for climbing but one beautifies the urban environment while accomplishing the design intent.

2. Actual Risk Approach

Identify neighbourhood crime levels and crime types, then design for specific activity.

Start the design process (as with any design) by identifying the activity to be designed for. Typically this is done by using a program or design brief and undertaking site analysis (refer to CPTED Neighbourhood Analysis Process and CPTED Site Analysis Form under the documents link). Having a sense of the levels and types of crime and nuisance activities surrounding a site is important so that design solutions can address specific activities.



Crime and nuisance are very specific types of activity in the bigger world of activities that take place in the urban environment. Even more so, there are few crimes and nuisance activities that physical design of buildings and public outdoor space can have an impact on. For example, cheque fraud and other white collar crimes are not often the subject of CPTED. The types of activities that can best be addressed by CPTED typically boil down to only a few activities:

  Theft from Auto
  Theft of Auto
  Break and Enter (Burglary)
  Robbery (mugging)
  Specific types of Assault

Nuisance Activity

  Mischief
  Skateboarding
  Graffiti

3. Designing to Reduce "Fear of Crime" versus Actual Risk

 

Once the specific types and levels of crime and nuisance activities have been identified, and design has focused on reducing these activities, then check to add fear reducing design where appropriate. Research has shown that people have a natural fear of places that are isolated, unkempt and dark, to name a few (refer to Crime Basics Section). However, research also confirms that actual risk of crime rarely occurs in these fearful places. In other words, people have fear of many places that are actually very safe. To complicate things further, people often do not have fear in those few places where there is actual risk. Design professionals tend to misunderstand the importance of designing to reduce actual crime in places with risk of violent crime.

 

 

 

Fear reducing design should only be undertaken after opportunity for actual violent crime has been reduced and where risk of violent crime is exceptionally low. For example, in residential underground parking, where violent crime is very rare (refer to Preventing Crime in Multi-Residential and Mixed-Use Parking Garages section), where stealing from cars is most prevalent, then it is appropriate to add features such as white walls and glass lobbies to reduce natural fear that people have in confined, isolated places.

 

However, caution should be used if there is any significant risk of violent crime. For example, if a dark pathway has lighting added to make it feel safe for pedestrians, this may inadvertently lead people into a location where there is risk of violent crime. This is one important reason why the designer must have knowledge of what type of crime is occurring in an area before undertaking any design to reduce feelings of fear without also creating designs that reduce actual risk of crime.

 

One solution for the dark pathway where there is risk of violent crime, is to create an alternate route for pedestrians where risk of crime is low such as along a commercial street (see Design Principle: 16. Alternate Routes).

 

4. Encourage Watching

 

This principle of encouraging watching is the same as the CPTED principles of surveillance and eyes on the street but by changing the valuation from a militaristic term such as surveillance to a typical human behaviour, such as watching, the possibilities for design are improved.

 

Informal Watching

Informal watching is when people are driving or walking on a street and are aware of the surrounding activities but are not primarily engaged in watching. This type of watching has informal effects on the public realm by setting levels of social activity, noting that the character and culture of an area will influence the type and levels of activities.

Engaged Watching

Engaged watching is when people are, for example, sitting in a sidewalk café, sitting in a public plaza or on a semi-private front porch and are primarily engaged in watching; people watching. This type of watching can have a more formal regulatory effect on activities in the public realm.

Another example is the window at the kitchen sink which overlooks the public or semi-public area. Even though, activity at the sink is the primary activity, a distraction is provided by the view from the window and generally increases to a type of engaged watching from this semi-private residential kitchen function.

In terms of watching, in the North American context, from residential units, some of the functions that happen in the spaces of a residence are less private than others. For example, a kitchen can tolerate less privacy than a bedroom. Therefore, more opportunity to encourage watching is afforded from semi-private functions in a residential unit.

 

semi-private residential functions

private residential functions

kitchen

bedrooms

working den

bathrooms

kitchen eating area/breakfast nook

living room with television


5. Create a Sense of Ownership / Claiming Public Space

 

This principle of creating a sense of ownership and claiming the public realm is the same as the CPTED principles of territoriality and defensibility but by changing the valuation from a militaristic term to a more common urban activity such as claiming ownership over public space, the possibilities for design are improved.

 

 

Design of the building and the grade level uses has important impacts on the activity that takes place on adjacent public streets, lanes or open spaces. Almost any opportunity to extend the sense of ownership of residents or commercial uses at the grade into the adjacent public space will have a positive effect on crime and nuisance. This can be in any type of active use on the street including industrial areas where an entry lobby with front desk or office functions overlook the street during business hours, noting that reducing opportunities for break and enter (burglary) must also be addressed if the industrial area is adjacent to a higher crime neighbourhood.

 

6. The Street as a "Functioning Unit"

 

A street in the North American context with cars, pedestrians on sidewalks and an active use at grade on each side of the street (as opposed to uses raised significantly above or below grade), functions as a social unit. The type of social activity is firstly influenced by the populations that may be on pathways in the area but secondarily influenced by the physical environment. By removing a physical element of the 'functioning unit' such as vehicles or active uses on the street, the unit becomes increasingly marginalised. As a design principle, removal of any one these elements and public areas can become eroded and an increase in some types of crime and nuisance activity can result.

 

It is important to note that some types of crime such as robbery and mugging depend on a "steady target flow" and are most often associated with areas where there is, firstly, a presence of high risk populations, secondly, where there are lots of people and thirdly, where there is limited guardianship of watchers. However, most types of crime and nuisance such as car crime and break and enter (burglary) tend to be reduced when associated with a street as a "functioning unit".

 

7. Relationship of the Residential Unit to the Street



  In a North American context, there are design elements of ground level residential units which can promote watching and ownership of the street that will reduce opportunities for crime such as break and enter (burglary) and nuisance activity. The levels of security design should reflect the crime level of the neighbourhood. The elements of a successful relationship to the street are:

 - residential floor level raised slightly above grade 1.5-4 ft.
  - front door facing the street with direct steps from the street to the door with porch or stoop,
  - front door and hardware to resist break and enter depending on crime levels in neighbourhood,
  - uses facing the street semi-private and active such as kitchen nook or kitchen (assuming traditional family residential),
  - two story townhouses to allow privacy retreat to the second floor,
  - ideally both front and back access to townhouse from both the street and the back of the unit, small paned windows with extra hardware in higher crime neighbourhoods, possibly grillwork in high crime neighbourhoods, operating windows placed higher,
  - no areas of concealment outside of windows or doors, where the residential looks out over the street,
  - setback from the street property line min. 4 ft., max. 12 ft.

8. Relationship of the Commercial Unit to the Street

Commercial uses should be located at street grade, located at the fronting property line with large glass display window area. Where possible, outdoor seating and outdoor display of goods should be encouraged. This commercial street formula projects a positive image. Bars on windows detracts from the positive image. Bollards in front of windows can also detract from the image.


Alternatives to providing bars on windows can be extra thick laminated glass, protective film on the glass, smaller panes window pattern up to approximately 6 ft. height and decorative grillwork.



9. Sending the Wrong Message: Bars on Windows, Low Voltage Lighting and Fortressing

 

So many security features such as bars on windows, lighting, poor lighting, fencing and gating send a message that preventing crime is more important than increasing livability and beauty. Bars on windows send a clear message that "crime has happened here" and erodes the neighbourhood fabric. As the skilled design professional, there are many ways to solve a security problem without detracting from the environment. This should always be the goal.

 

 

 

10. Cut-throughs and Multi-Access Sites

 

Creation of pedestrian pathways (whether intentional or otherwise) that cut-through a site, usually increases risk of crime and nuisance behaviour on that pathway. This is based on the concept that "crime happens on pathways and at activity nodes where there is a presence of high risk populations". Therefore, whether crime will increase or not, depends on who uses the path. However, under most circumstances, these pathways will naturally have higher levels of crime and nuisance. Pathways and the buildings on the pathways should be carefully reviewed to ensure design reduces opportunities for crime and nuisance activity through the use of defining public/private areas to create a sense of ownership (territoriality), encouraging watching and engaged watching (surveillance) by surrounding guardians, by locating vulnerable access points to personal property such as cars, out of the awareness spaces of the potential offender and within the view of residents or other guardians.

 

 

11. Seamless Connection to the Street for Public Places/Parks

 

One concept of traditional park design has been to create an oasis within the city, a reprieve from the noise and congestion. Thus, many traditional park designs turned their backs on the city with a strong landscape barrier at the street. Under many circumstances, this can increase risk of crime and nuisance activity. However, this depends on who is watching this space and what populations are in the area or passing through the area. If there are no guardians directly adjacent to a public area/park then the general principle of seamless connection to the street applies where the edge between the street and the public space/park is seamless. Allowing views into the public space/park also increases imageability of the park. However, consideration should also be given to the presence of activities such as drug markets and prostitution. These activities depend on lots of people and the open adjacent public space can increase opportunity for drugs markets and prostitution.

 

 

12. Clear and Clean Visibility

 

The absence of nooks, alcoves, backwater areas in a location that has high mischief and is poorly watched can reduce the mischief activity by being easily visible to anyone that may pass by on a street or lane. For example, the back of buildings, on a lane, should be designed to be "clear and clean" without nooks or alcoves so that visibility of the area is nearly instant.

 

13. If You Light It, They Will Come: The Question of Lighting

 

Lighting is often chosen as the primary method of making a place feel safer. Under many circumstances, increasing lighting levels will increase crime activity. In injection drug abuse neighbourhoods, light is needed to find a vein for injection. In some parks, the presence of lighting creates an opportunity for young people to hang out, often with an increase in mischief and vandalism of the lighted area. In buildings and public areas and streets, standard lighting levels are regulated by by-laws and standards and these provide sufficient illumination under most circumstances. For example, in parking garages or public streets, lighting levels are standardized and provide sufficient levels to reduce opportunities for crime and nuisance behaviour. Therefore, the rule of thumb for lighting can be as follows; lighting should be used to improve the view of any adjacent guardian, to improve watching opportunities, and lighting should always set a tone of beautifying or enhancing the environment while achieving other design objectives. When considering lighting, the question should be asked; if the lighting changes (either increased or decreased to total darkness), who will be attracted to the area?

 

14. Break and Enter: Areas of Concealment Versus Privacy

 

On ground level residential units, the design of the adjacent outdoor area is an important consideration. Research has shown that an area outside the windows and doors of the ground level unit which allows concealment for a person to hide while breaking-in is sought after by thieves. The skilled design professional thus has to balance the need for privacy on outdoor patios with the creation of an area of concealment.

 

 

This image shows that privacy for patios can be achieved without creating areas of concealment in front of vulnerable sliding doors.

 

15. Awareness Spaces: Removing a Potential Target

 

Removing a potential target (something to steal) from the awareness space of the potential offender is an important design consideration. For example, a perimeter exit stair to underground parking which is exposed to the lane with few watchers or guardians, creates an opportunity for access to cars for theft. Relocating the perimeter exit stair to where the residents of the building can watch it and to where the potential offender can not see it, will result in an effective method of reducing opportunities for crime.

 

 

16. Alternate Routes

 

A path or route may change at different times of the day or night i.e. a pathway through a park that seems pleasant during the day may become fearful at night. Providing an alternate, less convenient route along the street for more fearful times can be a design solution that reduces fear, and where there is actual risk of crime such as robbery or assault, it can also reduce risk of actual crime.

 

 

17. Street Closures

 

Street closures have been shown to be effective in some circumstances particularly where there is street prostitution and illegal drug markets. Most prostitution areas depend on cars for circling and pick up. However, the street closure alone will generally not succeed without an infusion of community resources and other programs to support the physical enhancements. It is important when considering a street closure or redirecting a street to ensure that regular activities and amenities are sustained.

 

 

18. Positive Effect on Surrounding Areas

 

Research has shown that successful crime prevention programs in one area sometimes have a positive effect on adjacent areas even though they may not have received any resources.

 

19. Infusion of Community Resources

 

Looking closely at many programs throughout North America developed under the name of CPTED or for street closures will show that part of the success of these programs was not just the resulting physical improvements but the community consultation, community support and programs improvements. This infusion of resources often has a significant positive effect.

 

20. Infusion of Legitimate Populations

 

When a neighbourhood has a larger than average percentage of high risk populations (perhaps up to 10%) that live in or pass through that neighbourhood, then the effects of too many people involved in illegal activities can be turned around by an infusion of legitimate populations. (Legitimate populations being those that do not take part in illegal activities.) An example would be where an area changes from an industrial use to medium or high density, market residential (or with partial non-market) adjacent to or within a medium crime neighbourhood, the legitimate activities of the new residents will tend balance or dominate the existing illegal activities. However, in high crime neighbourhoods, introduction of legitimate populations should be carefully considered. This principle is similar to the principle of neighbourhood gentrification.

 

21. Positive Effects of Management Programs

 

Environmental design is only one of the many important ways to reduce opportunities for crime and nuisance activities. Good management programs and security programs have important positive impacts and can be used where there are limited alternatives for physical design solutions.

 

22. Neighbourhood Genesis to Crime

 

In most cases, crime levels change slowly over time. If a crime generator such as a poorly managed pub moves into an area, it will often be offset by concerned neighbours or other moderating uses. However, in some cases, if a crime node, such as a mass transit station, comes into a neighbourhood already struggling with crime issues, this may tip the balance and begin the erosion of the neighbourhood and genesis to increasing crime levels.

 

23. Exterior Corridors

 

Multiple residential apartment buildings with exterior circulation corridors are often the target of higher levels of theft. The exterior corridors at the ground level and within easy climbing distance to the second or third floor can allow easy access to numerous doors leading to building exits and underground parking where theft from automobiles is the primary target. Secondarily, opportunities for breaking into residences can also increase.

 

 

24. Pedestrian Underpasses

 

The rule of thumb is to make the underpass as wide as it is long.

Pedestrian underpasses generate a lot of fear; they limit movement options, reduce visibility and increase isolation. They are often dark and are poorly maintained. All of these increase feelings of fear.

 

 

The actual risk associated with the underpass follows the orders of crime determiners. If there are high risk populations in the area then the underpass may attract actual risk of violent crime and nuisance behaviour such as graffiti and vandalism.

 

Is Good Design Also Safe Design?

 

Food for thought...

 


© Copyright Design Centre for CPTED Vancouver 2003 - 2010