Crime Prevention Through Environmental Design (CPTED) is a set of building and property design principles used to discourage crime. Rather than rely on guards, alarm systems, locks and other security devices, CPTED used a building or property's natural features to deter criminals.
CPTED principles are based on anticipating the thought processes of a potential offender, and creating an environment that discourages follow-through. When these principles are put into practice the resulting environment - including the building and its surroundings - will discourage or impede criminal behavior, and at the same time encourage honest citizens to keep a watchful eye.
The four principles of CPTED are
- Natural Surveillance
- Natural Access Control
- Territorial Reinforcement
- Maintenance
In this article, I will discuss the principle of territorial reinforcement, and suggest some ways to put this principle into practice.
The purpose of territorial reinforcement is to create a clear distinction between public and private property. This is important for two reasons: legitimate occupants have a sense of ownership and will notice people who don't belong; intruders, on the other hand, will have a hard time blending in. Here are some ways to implement territorial reinforcement:
Establish Borders
You can make a clear distinction between public and private spaces through natural as well as artificial means. Hedges and other landscaping features can be an attractive way to mark the boundaries of your property. Waist high fences, while easy to climb over, are an effective way to establish boundaries. When defining your property lines, be sure to keep landscaping and fences low enough that they will maintain clear site lines and not provide new hiding places.
Use Security Signage
If you use and alarm or camera system, then yard signs and window stickers can add to their deterrent power. Posting these signs in prominent places puts potential offenders on notice that you will record and respond to criminal activity.
Summary
Territorial reinforcement is not intended to prevent someone from entering an area; if you need to keep someone out then you should rely on guards, locks, gates, barbed-wire fences and similar methods. Rather, the purpose of territorial reinforcement is to send a message to potential offenders that this space belongs to someone else. When combined with the other elements of CPTED, it can be an effective deterrent to crime.
A Checklist
Here is a quick checklist that you can use to implement territorial reinforcement.
- Are my property lines clearly marked?
- If not, can I add hedges or fences to mark my property?
- If alarm or CCTV systems are in use, have I clearly announced that fact with security signage?
- Are any of my fences or hedges blocking site lines or creating hiding spaces?

