Surveillance Strategies

The 5 D’s of Outdoor Perimeter Security

Outdoor perimeter security is an often-overlooked area of physical security design that can dramatically improve the effectiveness of a facility’s security system. If you are involved in designing or managing physical security the infrastructure located in the buildings likely consumes the majority of your budget. However, small investments in outdoor perimeters can provide significant protection to the building’s assets well before the other, more costly, measures are encountered. These outdoor perimeters can serve as a valuable line of defense for a physical security plan because they add distance, time and scale to a physical security plan that cannot be achieved within the building itself.  If designed correctly, outdoor preventative measures can reduce the cost of building security. In all physical security designs outdoor perimeters should be included as a supportive element.

To correctly utilize the outdoor perimeter requires that the security plan take a holistic and complete assessment of the outdoor and indoor areas. A holistic perimeter reference design is the 5D’s of perimeter security. This design focuses on a key objective for each specific perimeter, and layers the perimeters from outside the facility to inside the secured buildings. The 5D’s starting from the outside are: Deter, Detect, Deny, Delay and Defend.  

The 5D perimeter protection design can reduce the overall cost of a facility’s security system and improve the effectiveness of the plan. Focusing the security objectives at each perimeter layer on a specific task, and designing the system in such a way that takes advantage of special purpose security systems achieve this. The following provides an overview of the key principles behind a 5D perimeter security design.



The deter perimeter is the farthest one from the location of the assets and is often a mix of physical infrastructure such as fences and lighting. The security objective on this perimeter is to deter the criminal from even attempting a breach of the system. Deterrence is a psychological battle, and when the security department wins, the criminal activity never starts. Applying surveillance technology along the deter perimeter typically requires the use of overt, large enclosures, which make it obvious to all approaching the perimeter that they are under surveillance. Signs saying “no trespassing” or “area under surveillance” also aid in communicating a deterrent message to unauthorized persons.



The detection perimeter’s security objective is to monitor large areas of space to accurately detect possible unauthorized intrusion in time to respond appropriately. Surveillance camera technology, especially megapixel cameras, is very effective as an accurate detection tool. Important objectives are the timely notification to security personnel, and having the ability to digitally or optically zoom into the area where intrusion was detected.



The objective at the deny perimeter is to keep unauthorized persons out, while allowing authorized persons to enter. To perform this function the deny perimeter typically has access control technology or a manned security gate at the point of entry. The intention of surveillance at this point is to provide visual verification to the biometric or card access system.



The delay perimeter’s objective is to slow down an active intrusion enough to force the intruder to give up, or allow the security team to respond. Often, interior locking doors or other physical barriers are used to slow down the intrusion. Surveillance cameras can be used inside the delay perimeter to provide situational awareness and measure the effectiveness of the delay countermeasures.



The defend perimeter is typically a security personnel response that attempts to apprehend the intruder.  Surveillance is used at this perimeter to record the apprehension and determine the effectiveness of the response.  This final perimeter often includes the involvement of law enforcement and typically overlaps the other perimeters.


Keys to Outdoor Perimeters

The general rule is that the farther away from a secured building the more expensive are the security measures. This holds true for cameras, sensors and access control systems. Designing outdoor systems requires detailed upfront planning because of the wide range of operating conditions to which the security systems will be exposed. For cameras, lighting and weather conditions are the biggest problems the system will have to overcome through infrared light and motion sensors. Holistic design processes that combine both indoor and outdoor perimeters, similar to the 5D’s, will provide the most effective physical security systems.   

Did you enjoy this article? Click here to subscribe to Security Magazine. 

Recent Articles by Keven Marier

You must login or register in order to post a comment.



Image Galleries

ASIS 2013 Product Preview

ASIS International 59th Annual Seminar and Exhibits, September 24-27 in Chicago, Illinois, will include an exhibit hall packed with innovative security solutions. Here are some of the products that will be shown at ASIS this year.


Virtualization and Data Center Security: What You Need to Know for 2014

Data centers are increasingly becoming the center of the enterprise, and data center and cyber security is following the same path for security departments. According to Justin Flynn, a consultant at the Burwood Group, the virtualization of data centers allows enterprises to scale more easily and faster, with a smaller footprint.

However, hosting enterprise data in the cloud can make intrusion detection more difficult – how can enterprise security leaders team up with other departments to keep aware of cyber risks and traffic, and physical and data compliance during the virtual transition? How can CISOs and CSOs discuss cyber threats with the C-Suite to get the resources they need? And how can the proper infrastructure test and verify possible malicious attacks? 

More Podcasts

Security Magazine

April 2015 security magazine cover

2015 April

In this April 2015 issue of Security, find out how to keep your enterprise resilient after a disaster in 2015. Also discover how to strike a balance between design basis threats and active shooter threats and see what's in store for the 2015 RSA Conference.

Table Of Contents Subscribe

Body Cameras on Security Officers

Body cameras are being used increasingly by police in cities across the U.S. Will you arm your security officers with a body camera?
View Results Poll Archive


Effective Security Management, 5th Edition.jpg
Effective Security Management, 5th Edition

 Effective Security Management, 5e, teaches practicing security professionals how to build their careers by mastering the fundamentals of good management. Charles Sennewald brings a time-tested blend of common sense, wisdom, and humor to this bestselling introduction to workplace dynamics. 

More Products

Clear Seas Research

Clear Seas ResearchWith access to over one million professionals and more than 60 industry-specific publications,Clear Seas Research offers relevant insights from those who know your industry best. Let us customize a market research solution that exceeds your marketing goals.


Facebook 40px 2-12-13 Twitter logo 40px 2-12-13  YouTube  LinkedIn logo 40px 2-12-13Google+

Vertical Sector Focus: Critical Infrastructures

criticalhomepagethumbFrom terrorism to vandalism, it’s preparedness, response, training and partnerships. Learn about some of the critical security issues facing this sector.

Visit the Critical Infrastructure page to read more.