Effective Fire Safety | Active & Passive Fire Precautions

Understanding the types of fire safety precautions and how they can be used to complement and compensate for each other, can be useful when a building is under construction, or being renovated from a warehouse to flats, for example.

A fire safety design will address life and building survival through combining two categories of fire precaution - active and passive.

Active Fire Precautions

Active fire precautions are installations that usually monitor for the presence of a fire or smoke; or interact with a fire when it occurs.  The most common example of active fire precautions is Automatic Fire Detection (AFD).  An AFD system constantly reviews conditions within the building and reports back to the control panel.  Similarly, suppression systems, such as sprinklers, monitor conditions and, should a fire occur, the extinguishing media will be used to control or extinguish the fire.

Passive Fire Precautions

In contrast to active systems, passive fire precautions do not monitor a situation but are installed in most cases to strengthen the core and prevent the spread of fire. A common example of passive fire precaution is compartmentation, i.e. fire walls.  A wall is constructed using appropriate materials, with part of its purpose to prevent fire spread from one area to another, usually for a specified time.  The wall does not act or monitor the fire condition but can protect escape routes, for example.

Compartmentation is only one example of passive fire precautions, there are some precautions that act in a passive manner until they are heated, then their properties alter to achieve the desired objective.

Which precautions to choose?

There is rarely a clear cut right or wrong answer in terms of what precautions to adopt, however, as with most projects, costs will be an important factor.  It may be possible to specify systems that achieve life safety compliance based on an optimal cost basis.  

However, pure costing is often more complicated, with some precautions - such as a fire wall - only really attracting a 'capital cost', whereby once the precaution is built, it will require little in terms of maintenance and testing. However, active systems, by virtue of their very nature, will require testing, servicing and maintenance and are likely to have a product lifespan, after which they would need replacing.

Code Compliance/Compensation Features

Understanding how the types of fire precautions work and can help to support, and in some cases, compensate for each other will enable a code compliant, fire safe project.

For example, should fire compartmentation (passive precautions) be required by codes of practice, but deemed prohibitive to the design, active precautions could be offered as a compensatory feature.  Compartmentation is usually required to protect escape routes, thus reducing the time occupants spend in a potentially dangerous environment.  

The use of comprehensive AFD, ensuring that occupants receive early warning of a fire, will also ensure persons spend a reduced time in the same environment.  In this way, it can be seen that two very different fire precautions can achieve the same goal.

Your chosen fire engineers should understand the functional objectives of the code, which form the benchmark for life safety.  This, coupled with the project objectives, will ensure that the fire safety installations complement the design rather than suppress it.

If you would like to know more - or would like to arrange an appointment with one of our senior fire safety advisers - simply call Peter Gyere on 020 8668 8663.