Once an alarm is triggered, the police typically take up to 30 minutes or more to arrive. Anything that is going to happen after an intruder enters, is most likely going to happen within the first 15 minutes; be it theft, assault, kidnapping, murder, etc. By the time the police arrive, the damage is usually done, and more often than not, the intruders are long gone. In essence, time is the critical factor to ensure a safe outcome. The "Half Hour Principle™" requires that the occupants be kept safe from harm for at least 30 minutes from the time their alarm system is activated.

While Safe Rooms ("Panic Room") have been the focus of much public attention, as stand alone facilities in residential applications their effectiveness is questionable. However, when used in conjunction with a Safe Core, the Safe Room becomes an effective control and safety center which is an integral part of the overall Safe Environment. A Safe Core is typically a number of secure rooms through which the occupants can move freely.

In corporate applications, a stand alone Safe Room may provide an adequate level of protection. However, a Safe Core is generally specified in the final analysis.