Doors form an essential part of physical security and are often required to perform several functions, including:
- To control access for authorised personnel
- Permit an appropriate flow of people/materials etc.
- To work in conjunction with intruder detection systems (IDS), to detect unauthorised access
- To provide a barrier to delay the progress of an adversary
- To provide protection from specific types of threat, such as blast or ballistic
- To provide protection from fire and / or smoke ingress
- To provide a means of escape in an emergency
Security doors should be considered as a system, typically comprising the following components:
- Door leaf
- Door furniture
- Locking hardware
- Door frame
- Frame fixings
- Supporting structure (steel 'H' frames are often required to support heavy doors as the load imposed on neighbouring walls if often very high)
They may also have associated side and overhead panels.
Security doors should also integrate with sensors for intrusion detection and access control systems.
Whether they are part of the external façade, or form part of the boundary round a space within the building, it is important to define the security requirements for each door. Working from a security threat and risk assessment it should be determined which of the following types of attack the door needs to work against:
- Ballistic - people either trying to shoot at occupants through the door or to damage the door / door hardware in order to gain entry
- Manual forced entry - attackers using tools to try and force entry through the door
- Marauding Terrorist Attacks - attackers using bladed weapons, ballistics or IEDs followed immediately by forced entry to gain entry. NPSA has introduced a new standard which focusses on Marauding Terrorist Attacks (MTAS)
- Surreptitious entry - an attacker trying to infiltrate through the door leaving no indication of compromise
It is usual to have multiple security requirements that doors must fulfil. Where this is the case it is essential that the doors meet the various specified protection standards.